mm 


mm 


I 

■ii 

r 

-Ml 

i 

'!n!fl 

1 

1 

'}  •.-,:  ! 


iiU' 


m 


REPRINT  FROM 

SOIL    SCIENCE 

RUTGERS    COLLEGE 

Vol.  I  New  Brunswick,  N.  J.,  May,  1916.  No.  5 


STUDIES    ON    THE    DECOMPOSITION    OF    CELLULOSE 

IN  SOILS 

By 

I.  G.  McBeth 


STUDIES    ON    THE   DECOMPOSITION  OF  CELLULOSE 

IN  SOILS' 

By 

I.    G.    McBeth 

Introduction 
The  discovery  and  comprehension  of  the  biological  and  chemical 
forces  relating  to  the  decomposition  of  the  carbohydrate  materials  in  soils 
is  unquestionably  necessary  to  the  solution  of  many  problems  in  soil  fer- 
tility and  crop  production.  A  large  percentage  of  the  carbon  content  of 
the  plant  residue  is  found  as  a  constituent  of  the  celluloses.  These  com- 
pounds, because  of  their  refractory  nature,  must  first  be  attacked  by  a 
special  group  of  organisms.  An  accurate  knowledge  of  the  cultural  and 
biochemical  characteristics  of  tlie  organisms  involved  in  the  transforma- 
tion of  cellulose  into  less  refractory  compounds  is,  therefore,  obviously  of 
the  greatest  importance. 

Extensive  investigations  during  the  last  few  years  have  shown  that  the 
decomposition  of  cellulose  is  by  no  means  limited  to  the  bacteria  of  soils. 
The  filamentous  fungi  possessing  this  power  are  very  numerous  and 
many  species  are  exceedingly  active  agents  in  the  destruction  of  cellulose. 
In  the  humid  soils  of  the  East  the  filamentous  fungi  are  perhaps  of 
greater  importance  than  bacteria  in  the  destruction  of  cellulose,  while  in 
the  semi-arid  soils  of  the  West  tlie  reverse  is  apparently  true.  Several 
species  of  Actinomyces  are  also  known  to  have  tlie  power  of  dissolving 
cellulose  and  because  of  their  general  distribution,  these  organisms  are 
undoubtedly  a  factor  in  tlie  destruction  of  cellulose  in  soils.  This  paper 
deals,  for  the  most  part,  with  investigations  of  cellulose-dissolving  bac- 
teria. 

Culture  Media 
Methods  for  the  preparation  of  cellulose  agar  and  other  suitable  cul- 
ture media  for  the  study  of  cellulose-dissolving  bacteria  have  been  dis- 
cussed, at  some  length,  in  earlier  publications  by  Kellerman  and  McBeth 
(29),  McBeth  and  Scales  (43),  Lohnis  and  Lochhead  (40),  Kellerman, 

^  Paper  No.  16,  Citrus  Experiment  Station,  College  of  Agriculture,  University  of  California, 
Riverside,  California. 

Received  for  publication  March  30,  1916. 

A  bibliography  of  the  literature  relating  to  cellulose  destruction  is  included  and  reference  is 
made  by  numbers  to  "literature  cited"  (p.  481  ). 

(437) 
(31) 


3505^^1 


438  SOIL  SCIENCE 

McBeth,  Scales,  and  Smith  (30),  and  Scales  (71).  The  cellulose  agar 
prepared  as  described  in  the  above  mentioned  publications  has  given  very 
satisfactory  results  not  only  with  cellulose-dissolving  bacteria,  but  also 
with  filamentous  fungi.  The  medium  also  appears  to  be  well  adapted  to 
the  study  of  cellulose  destruction  by  species  of  Actinomyces.  We  have 
frequently  observed  colonies  of  Actinomyces  which  dissolve  the  cellulose 
very  rapidly  in  the  cellulose  agar,  forming  a  clear  enzymic  zone  about  the 
colony  which  furnishes  unmistakable  evidence  of  the  cellulose-dissolving 
power  of  the  organism.  Krainsky  (36)  in  his  recent  studies  of  the  Acti- 
nomyces, has  reported  the  cellulose  agar  plate  method  as  unsatisfactory 
for  determining  the  cellulose-dissolving  power  of  these  organisms.  How- 
ever, he  was  able  to  demonstrate  the  cellulose-dissolving  power  of  several 
species  of  Actinomyces  by  the  use  of  paper  pulp  or  strips  of  paper  on 
silica  jelly,  and  also  by  means  of  cellulose  hydrate  prepared  by  the  zinc 
chloride  method.  The  reason  for  the  failure  of  Krainsky  to  secure  satis- 
factory results  with  the  cellulose  agar  plate  method  is  not  clear.  How- 
ever, since  these  organisms  grew  luxuriantly  upon  the  cellulose  agar  pre- 
pared by  us  and  dissolved  the  cellulose  very  rapidly,  it  would  seem  that 
the  tmsatis factory  results  reported  by  Krainsky  may  be  due  to  certain  in- 
attention to  details  in  the  preparation  of  the  cellulose  precipi- 
tate. In  order  to  secure  a  uniformly  fine  amorphous  precipitate,  it 
is  necessary  to  carry  out  the  operations  with  considerable  care. 
It  is  believed  that  much  of  the  difficulty  experienced  in  the  prepa- 
ration of  precipitated  cellulose  is  caused  by  precipitating  in  solu- 
tions that  are  too  concentrated.  If  either  the  copper-ammonium-cel- 
lulose solution  or  the  acid  used  in  precipitating  the  cellulose  is  too 
concentrated,  a  product  is  frequently  secured  which  is  not  only  dif- 
ficult to  wash,  but  is  very  unsatisfactory  as  a  culture  medium.  A  very 
uniform  and  satisfactory  amorphous  precipitate  can  be  secured  by  adher- 
ing strictly  to  the  following  method  which  is  a  slight  modification  of  tiie 
method  originally  proposed. 

1.  Pour  1  liter  of  ammonium  hydroxide,  sp.  gr.  0.90,  into  a  glass- 
stoppered  bottle ;  add  250  c.c.  of  distilled  water  and  75  gm.  of  pure  cop- 
per carbonate;  shake  the  solution  vigorously  until  all  the  copper  is  dis- 
solved.    (From  10  to  15  minutes  is  ordinarily  required.) 

2.  To  the  copper-ammonium  solution  add  15  gm.  of  high  grade,  sheet 
filter  paper ;  shake  vigorously  at  intervals  of  10  minutes  for  one-half  hour. 
Examine  the  solution  carefully  to  see  that  the  paper  is  completely  dis- 
solved. If  any  particles  of  paper  remain  in  the  solution,  the  shaking  must 
be  continued  until  the  solution  is  perfectly  clear. 

Dilute  250  c.c.  of  the  ammonium-copper-cellulose  solution  to  10  liters 
with  tap  water ;  add  slowly  with  frequent  shaking,  a  weak  hydrocloric  acid 
solution  prepared  by  adding  500  c.c.  of  concentrated  acid  to  10  liters  of 


THE  DECOMPOSITION  OF  CELLULOSE  IN  SOILS  439 

tap  water.  Continue  the  addition  of  the  acid  until  the  blue  color  disap- 
pears ;  add  a  slight  excess  of  acid,  shake  thoroughly  and  allow  to  stand  a 
few  minutes.  The  finely  precipitated  cellulose  will  rise  to  the  top,  due  to 
the  large  quantity  of  free  hydrogen  liberated  in  the  precipitation  process. 
Shake  the  solution  vigorously  at  intervals  of  a  few  minutes  to  dislodge 
the  hydrogen.  As  soon  as  tlie  free  hydrogen  has  escaped  the  cellulose 
will  settle  rapidly. 

3.  Wash  through  repeated  changes  of  water  until  free  from  copper 
and  chlorine.  After  the  washing  is  complete,  bring  the  cellulose  in  the 
solution  up  to  0.5  per  cent,  by  allowing  to  settle  a  few  days  and  siphon- 
ing off  tlie  clear  solution  or  by  evaporating.  Add  the  nutrient  salts  de- 
sired together  with  1  per  cent  of  thoroughly  washed  agar;  heat  in  auto- 
clave or  boil  until  the  agar  is  dissolved;  tube  and  sterilize  in  the  usual 
way. 

Action  of  the  Cellulose-Dissolving  Bacteria  Studied  on  the 
Cellulose  of  Plant  Tissues 

While  the  preparation  of  cellulose  agar  from  precipitated  cellulose  as 
described  above  has  proven  quite  satisfactory  for  the  isolation  and  study 
of  organisms  which  dissolve  typical  cellulose,  such  as  is  found  in  filter 
paper  or  in  cotton  fiber,  it  does  not  make  possible  a  study  of  the  action  of 
the  organisms  on  the  celluloses  in  plant  tissues  such  as  are  ordinarily  add- 
ed to  the  soil,  as  stubble,  roots,  green  manure,  etc.  Since  the  term  "cellu- 
lose" connotes  a  group  of  substances  rather  tlian  a  single  chemical  com- 
pound, it  seems  important  that  methods  be  devised  which  will  make  pos- 
sible a  comparative  study  of  the  action  of  the  cellulose-dissolving  organ- 
isms isolated  from  the  soil,  upon  the  cellulose  of  different  plants  and  also 
of  the  same  plants  at  different  stages  of  maturity.  In  the  young  plant 
cells  the  walls  contain  almost  pure  cellulose,  but  as  the  plant  developes  the 
cellulose  originally  formed  is  altered  by  the  addition  to  it  of  various  sec- 
ondary products  known  as  encrusting  substances.  The  nature  and  prop- 
erties of  the  resulting  fiber  depends,  of  course,  upon  the  nature  of  the 
substances  deposited. 

Since  many  of  the  cellulose-dissolving  organisms  attack  not  only  the 
celluloses,  but  many  other  plant  substances  such  as  the  starches,  sugars, 
and  proteins,  it  is  necessary  in  studying  the  action  of  these  organisms  on 
the  cellulose  of  different  plant  tissues,  other  than  that  of  cotton  fiber,  to 
separate  the  cellulose  from  the  other  compounds  with  which  it  is  more  or 
less  closely  associated  in  the  plant.  It  is  also  important  that  the  purified 
cellulose  be  separated  into  very  fine  particles  such  as  will  permit  the 
preparation  of  a  satisfactory  cellulose  agar.  Finely  divided  pure  cellu- 
lose suitable  for  the  preparation  of  cellulose  agar  may  be  prepared  from 
plant  substances  as  follows : 


440  SOIL  SCIENCE 

1.  Grind  a  quantity  of  the  dry  plant  substance  to  a  flour  and  sift 
through  bolting  cloth  to  remove  all  coarse  material. 

2.  Boil  50  gm.  of  the  sifted  flour  in  a  2  per  cent  potassium  hydrate 
solution  for  one-half  hour;  pour  into  a  large  bottle  or  carboy  and  wash 
through  repeated  changes  of  water  until  free  from  potassium. 

3.  Expose  the  washed  material  to  the  action  of  chlorine  at  ordinary 
temperatures  for  one-half  hour.  Wash  as  before  imtil  the  chlorine  is  re- 
moved. 

4.  Subject  to  a  second  alkaline  hydrolysis  by  boiling  with  2  per  cent 
caustic  soda  for  one-half  hour.  Wash  until  the  solution  is  no  longer  al- 
kaline. I      -^-'i^ 

The  cellulose  is  thus  isolated  in  a  very  pure  state,  and  if  the  grinding 
of  the  plant  material  has  been  sufficiently  fine,  the  finely  divided  cellulose 
prepared  in  this  way  is  quite  as  satisfactory  for  the  preparation  of  cellu- 
lose agar  as  that  prepared  from  filter  paper  by  tlie  ordinary  method. 

In  the  present  work  it  has  not  been  possible  to  make  an  extensive 
study  of  the  decomposition  of  the  celluloses  in  different  plant  substances. 
However,  it  has  been  demonstrated  that  the  cellulose-dissolving  bacteria 
isolated  from  soils  by  means  of  the  cellulose  agar  plate  method,  have  the 
power  of  dissolving  the  cellulose  of  alfalfa.  Twenty-five  species  of  cellu- 
lose-dissolving bacteria  were  plated  to  cellulose  agar  containing  pure 
cellulose  from  the  alfalfa  plant  and  in  every  instance  the  cellulose  was 
dissolved  as  readily  as  that  prepared  from  filter  paper  by  the  ordinary 
method. 

Discussion  of  General  Characteristics  of  Cellulose-Dissolving 

Bacteria 

The  author's  exhaustive  studies  of  a  large  number  of  soils  from  widely 
separated  regions  have  shown  that  there  are  numerous  species  of  bacteria 
which  have  the  power  to  destroy  cellulose.  All  of  the  forms  studied  are 
rod-shaped  organisms  varying  in  length  from  .8  to  3.50  fi.  Involution 
forms  have  been  observed  for  only  three  species.  Five  species  have  been 
found  to  produce  spores.  Twenty-seven  of  the  thirty-six  species  isolated 
are  motile.  The  arrangement  of  the  flagella  on  the  motile  forms  shows  that 
seven  species  belong  to  the  genus  Pseudomonas  and  twenty  to  the  genus 
Bacillus.  All  species  stain  readily  with  the  aniline  dyes.  All  are  facul- 
tative in  nature,  but  invariably  develop  most  rapidly  imder  aerobic  con- 
ditions. With  some  species,  the  development  under  anaerobic  conditions 
is  very  slow.  All  species  grow  well  from  20°  to  37.5°  C,  and  some 
forms  have  been  found  to  develop  at  temperatures  as  high  as  45°  C,  but 
much  more  slowly  than  at  the  lower  temperatures.  The  optimum  tem- 
perature for  most  species  seems  to  lie  between  28°  to  33°  C. 

With  two  exceptions,  the  cellulose-destroying  bacteria  form  more  or 
less  growth  upon  ordinary  culture  media  such  as  beef  gelatin,  beef  agar, 


THE  DECOMPOSITION  OF  CELLULOSE  IN  SOILS  441 

etc.  Of  the  thirty-four  species  which  grow  upon  gelatin,  nineteen  Hquefy 
the  gelatin.  Many  forms  produce  a  growth  upon  beef  agar  and  potato 
agar  slopes  in  24  hours.  A  few  species  grow  quite  luxuriantly  upon 
potato  cylinders,  but  in  most  cases  no  growth  or  only  a  scant  growth  is 
produced,  even  when  the  cultures  are  held  in  a  moist  chamber  for  30 
days.  Twenty-nine  species  produce  an  acid  reaction  and  three  an  alkaline 
reaction  in  litmus  milk.  Four  species  do  not  change  the  reaction  of  lit- 
mus milk.    The  milk  is  coagulated  or  digested  by  only  six  species. 

The  destruction  of  cellulose  can  be  secured  in  nutrient  solutions  con- 
taining ammonium  sulphate,  potassium  nitrate,  peptone,  casein,  or  aspar- 
agin  as  the  source  of  nitrogen.  Peptone  appears  to  give  the  best  results 
for  the  largest  number  of  organisms,  while  casein  is  least  satisfactory 
for  many  forms.  No  destruction  of  cellulose  has  been  secured  without 
the  addition  of  combined  nitrogen  to  the  nutrient  solution.  This  would 
seem  to  indicate  that  the  cellulose-dissolving  organisms  do  not  draw 
freely  upon  the  free  nitrogen  of  the  air  for  their  nitrogen  supply.  This 
hypothesis  is  further  strengthened  by  the  behavior  of  the  organisms  in 
dextrose  solutions.  When  dextrose  is  added  to  nutrient  solutions  con- 
taining combined  nitrogen,  many  of  the  cellulose-dissolving  organisms 
vigorously  attack  the  dextrose ;  but  when  the  nutrient  solution  is  care- 
fully freed  from  combined  nitrogen  the  dextrose  is  attacked  very  slowly 
and  little  or  no  fixation  of  nitrogen  is  secured. 

No  gas  is  formed  by  any  of  the  species  in  cellulose  or  other  carbo- 
hydrate broths.  The  quantity  of  acid  produced  in  carbohydrate  broths  is 
fairly  constant  for  the  species,  but  quite  variable  for  different  species. 
With  dextrose,  lactose,  maltose,  saccharose,  and  starch  the  quantity  of 
acid  produced  in  12  days  at  30°  C.  usually  lies  between  1  and  2  per  cent 
on  Fuller's  Scale.  The  amount  of  acidity  in  the  mannite  and  glycerine 
solutions  is  very  generally  less  than  1  per  cent,  and  in  many  cases  no 
acidity  is  produced  in  these  solutions.  Two  species  cause  no  change  in 
the  reaction  of  any  of  the  carbohydrate  broths.  B.  rossicus  gave  an  alka- 
line reaction  in  all  the  broths,  while  Ps.  effusa  gave  an  alkaline  reaction 
in  the  lactose  and  saccharose  broths.  The  alkaline  reaction  is  probably 
due  to  the  formation  of  ammonia  from  the  peptone  in  the  solution,  the 
ammonia  produced  being  more  than  sufficient  to  neutralize  any  acid 
formed.  In  Dunham's  solution  fourteen  species  produce  ammonia,  while 
twenty  forms  produce  a  compoimd  which  gives  typical  reactions  for  ni- 
trites with  the  Griess'  reagent  and  also  with  the  starch-iodide  and  the 
diphenylamine  solutions.  There  seems  to  be  no  reason  for  concluding 
that  the  substance  is  not  nitrite  except  that  nitrite  formation  has  been 
thought  to  be  restricted  to  a  particular  group  of  organisms  which  do  not 
grow  upon  ordinary  media.  The  quantity  of  nitrite  formed  by  the 
cellulose-dissolving  forms  is  small ;  in  most  instances  not  more  than  one 


442  SOIL  SCIENCE 

part  per  million  of  nitrogen  as  nitrite  is  produced.  However,  the  forma- 
tion of  this  small  amount  is  constant  and  is,  therefore,  of  considerable 
value  as  a  diagnostic  feature. 

Since  many  species  produce  nitrites  in  Dunham's  solution,  it  is  ob- 
vious that  erroneous  conclusions  might  be  drawn  from  the  use  of  a 
nitrate  broth  containing  peptone.  Peptone  has  therefore  been  left  out  of 
the  nitrate  broth  used  in  studying  the  nitrate  reducing  power  of  these  or- 
ganisms, and  a  small  quantity  of  starch  added  to  furnish  the  necessary 
carbon.  In  this  broth  many  of  the  species  reduce  nitrates  to  nitrites,  but 
only  four  forms  reduce  nitrates  to  ammonia. 

The  Occurrence  and  Activity  of  Cellulose-Dissolving  Bacteria  in 
Southern  California  Soils 

Examinations  of  69  soils  of  southern  California  for  cellulose-dissolv- 
ing bacteria  indicate  that  these  soils  contain  numerous  species  of  bacteria 
which  have  the  power  of  dissolving  cellulose.  All  of  the  soils  examined 
were  found  to  contain  one  or  more  active  cellulose-destroying  forms  and 
most  of  the  species  isolated  were  found  in  two  or  more  soils  from  widely 
separated  districts.  One  of  the  most  active  forms  (B.  imminufus)  was 
isolated  from  ten  of  the  sixty-nine  soils  examined.  From  the  southern 
California  soils  studied  fifteen  new  species  of  cellulose-dissolving  bacteria 
have  been  isolated  and  described.  In  addition  to  the  new  species  found, 
seven  species  previously  isolated  from  other  soils  have  been  identified. 
The  distribution  of  the  cellulose-dissolving  bacteria  found  in  the  southern 
California  soils  is  shown  in  Table  I. 

It  is  well  known  that  a  very  rapid  destruction  of  cellulose  occurs  in 
many  citrus  soils  of  southern  Colifornia.  The  question  naturally  arises 
whether  the  rapid  destruction  of  cellulose  in  these  soils  is  due  to  the 
presence  of  unusually  active  cellulose-destroying  organisms  or  to  favor- 
able conditions  which  make  possible  a  very  rapid  multiplication  of  the 
cellulose-dissolving  organisms  present.  From  the  studies  made,  it  is  evi- 
dent that  the  soils  are  abundantly  supplied  with  active  cellulose-destroy- 
ing bacteria.  Moreover,  some  of  the  most  active  forms  appear  to  have  a 
very  wide  distribution  in  the  soils  of  southern  California.  However,  with 
the  possible  exception  of  B.  inmiinutus  the  cellulose-destroying  bacteria 
found  in  southern  California  soils,  when  placed  under  standard  condi- 
tions, appear  to  be  no  more  active  agents  in  the  destruction  of  cellulose 
than  the  organisms  isolated  from  the  humid  regions  of  the  United  States. 
In  any  explanation  of  the  rapid  destruction  of  cellulose  in  these  soils  we 
must  take  into  consideration  the  activity  of  filamentous  fungi  and  possi- 
bly the  Actinomyces.  The  cellulose-destroying  fungi  are  unquestionably 
less  numerous  and  less  active  in  the  semi-arid  soils  of  southern  California 
than  in  the  humid  soils  of  the  eastern  part  of  the  United  States.  The 
same  is  apparently  true  of  the  cellulose-destroying  species  of  Actino- 
myces. 


THE  DECOMPOSITION  OF  CELLULOSE  IN  SOILS 


443 


^    & 


o 

u 
o 
o 

H 
D 
P3 

2 


3[[IA0Ulj\\ 


J3U}U[A\ 


BpUL'[dQ 


ui}snx 


B[nE<J  BJUBS 


jaSuBg 


opuEUiaj  UBg 


OpiSJDAty^ 


spireipaa 


OllIAJO^IOJ 


EUOpESBJ 


ElAOJUOJ^ 


3UO-)U0]\[ 


Sjnqspaoq 


pucmSiH 


3AoaSiiSij-[ 


EJOpUDO 


uojJ3[[n. 


SIAEQ 


BUIA03 


BUOJ03 


B}siA  Binq3 


BlIUOJJ 


X3p>(J3Q 


A\01SJEg 


3uiuuc[j 


Esnzy 


uo;3ui[JV 


6    S 


E 

2    E 


■J      C      u      3     5 

s  :h  ^  a  a 


^    E 


E    'e    -2 


::;   u:    ^ 


y     o     o     ^      .      .       .  -      -     -•     u     (J 


444  SOIL  SCIENCE 

The  writer's  extensive  studies  of  the  cukural  characteristics  of  cellu- 
lose-destroying organisms  has  shown  that  a  rapid  destruction  of  cellulose 
occurs  only  when  the  culture  medium  is  thoroughly  aerated  and  contains 
an  abundant  supply  of  available  nitrogen.  It  is  also  essential  that  fairly 
high  temperatures  be  maintained.  The  thorough  cultivation  given  most 
citrus  soils  in  southern  California  insures  thorough  aeration.  The  surface 
soil  to  which  the  organic  matter  is  usually  added  is  generally  well  supplied 
with  available  nitrogen.  The  soil  temperature  even  during  the  winter 
months  is  seldom  below  that  at  which  a  rapid  multiplication  of  the  cellu- 
lose-dissolving organisms  takes  place.  In  view  of  the  above  stated  condi- 
tions, it  would  seem  that  the  very  rapid  destruction  of  cellulose  in  these 
soils  is  probably  due  more  to  the  very  favorable  cultural  and  climatic  con- 
ditions which  make  possible  the  rapid  multiplication  of  the  cellulose-dis- 
solving organisms  in  these  soils. 

New  Species  of  Cellulose-Dissolving  Bacteria 
It  is  obvious  that  an  adequate  knowledge  of  cellulose  decomposition 
in  soils  must  be  based  upon  a  clear  understanding  of  the  character  of  the 
cellulose-dissolving  micro-flora  of  soils.  This  knowledge  can  be  obtained 
only  by  an  arrangement  of  the  organisms  studied  in  a  logical  system  of 
classification  such  as  will  make  possible  a  comparative  study  of  the  forms 
described.  In  the  establishment  of  the  points  of  differentiation  upon 
which  separation  may  be  based,  there  are  of  course  many  possible 
methods  of  procedure  varying  according  to  the  points  of  resemblance 
which  are  selected  as  important. 

In  working  out  the  description  of  new  species  of  cellulose-dissolving 
bacteria,  an  attempt  has  been  made  to  bring  out  the  individual  character- 
istics as  concisely  as  possible.  Many  of  the  data  called  for  by  the  card  of 
the  Society  of  American  Bacteriologists  seem  to  have  little  significance  in 
the  separation  of  members  of  this  group.  Moreover,  in  the  isolation  and 
classification  of  this  group  of  organisms  it  has  been  found  necessary  to 
prepare  several  new  varieties  or  culture  media  which  are  of  especial  im- 
portance in  the  classification  of  the  cellulose-dissolving  organisms,  but 
would  probably  be  of  little  imporance  in  the  classification  of 
ordinary  saprophytic  bacteria  in  soils.  So  far  as  we  are  able 
to  determine  none  of  the  cellulose-dissolving  organisms  isolated 
have  been  previously  described  as  saprophytic  forms.  In  view  of 
the  above  stated  conditions  and  the  fact  that  the  power  to  dissolve  cellu- 
lose forms  a  definite  basis  for  the  group,  we  believe  that  the  classification 
of  the  cellulose-dissolving  organisms  can  be  most  satisfactorily  accom- 
plished by  the  employment  of  only  those  media  which  are  of  especial  im- 
portance in  differentiating  the  members  of  this  particular  group  and  by 
using  only  those  characters  which  remain  constant  through  several  sets 
of  cultures. 


THE  DECOMPOSITION  OF  CELLULOSE  IN  SOILS  445 

Bacillus  alhidus,  n.  sp. 

Source  :     Soil  from  Tustin,  California. 

I.  Morphology. 

1.  Vegetative  cells :    Average  dimensions  1  x  .004  fx. 

2.  Endospores :    None  observed. 

3.  Flagella :     1  to  3  in  number ;  3  to  5  /x,  in  length. 

4.  Staining  reactions :    Gram  negative.    Stain  readily  with  the  aniline  dyes. 

II.  Cultural  Characteristics. 

5.  Agar  strokes,  5  days. 

Beef  Agar:     Scant,  white,  spreading  growth. 

Potato  agar:    Abundant,  white  to  grayish  white  growth,  spreading  over 

the  entire  slope. 
Peptone  starch  agar:     Moderate,  white  to  gray  white  growth. 

6.  Potato  cylinders:     No  growth  in  30  days. 

7.  Gelatin  stab:     Scant  growth  at  surface  and  perceptible  growth  along 

the  track  of  the  needle ;  in  5  days.    No  liquefaction  in  30  days. 

8.  Beef  broth,  5  days.    Not  clouded. 

9.  Litmus  milk:     Reddened  in  7  days,  neither  coagulated  nor  digested  in 

30  days. 
10.     Plate  cultures. 

Ammonia  cellulose  agar,  15  days. 

Form :      Colonies   at   the   immediate   surface   of  the  medium   are 

round,  those  located  a  little  beneath  the  surface  are  irregularly 

round. 
Size :     8  to  12  mm. 
Enzymic  zone:     Clearing  all  within  colony  after  15  days.     After 

30  days  the  colonies  show  an  enzymic  zone  of  1  to  2  mm. 
Elevation :     Saucer  shaped. 
Chromopenesis :     Entire  colony  is  vitreous  with  the  exception  of 

a  thin,  white  rim. 
Internal  structure :     Indeterminate. 
Edge :     Entire  to  undulate. 
Peptone  starch  agar,  5  days. 

Form :      Colonies    at    the    immediate    surface    are    round,    those 

slightly  below  the  surface  are  irregularly  round. 
Size :    2  to  3  mm. 
Enzymic  zone:     1  to  1.5  mm. 
Elevation :     Slightly  convex. 
Chromogenesis :    White  to  Hght  grayish  white. 
Internal   structure :     Coarsely  granular ;   granules   often  arranged 

in  clumps. 
Edge:    Entire  to  undulate. 
Beef  agar,  5  days. 
Form :    Round. 
Size :    1  to  1.50  mm. 
Elevation :    Convex. 

Consistency:     Soft;  colonies  from  10  to  15  days  old  become  brittle. 
Chromogenesis :     By  reflected  light  the  colonies  are  Hght  grayish 

white.     By  transmitted  light  they  appear  as  semi-transparent 

glistening  drops. 
Internal  structure :     Granular. 
Edge :    Entire. 


446  SOIL  SCIENCE 

Potato  agar,  5  days. 
Form :    Round. 
Size :    2  to  3  mm. 
Elevation :     Convex. 

Consistency :     Soft,  colonies  from  15  to  20  days  old  become  brittle. 
Chromogenesis :     Semi-transparent  white,  with  pearl-like  luster. 
Internal  structure:     Granular. 

11.  Filter  paper  broths,  15  days.     The  paper  is  reduced  to  a  thin,  filmy 

grayish  white  mass  which  readily  breaks  up  on  slight  agitation. 
The  paper  is  readily  attacked  in  solutions  supplied  with  ammonium 
sulphate  or  peptone;  but  is  much  slower  in  solutions  containing 
potassium  nitrate  or  casein  as  the  source  of  nitrogen. 
III.    Biochemical  Features. 

12.  Dunham's  solution,  10  days:     No  ammonia  produced;  no  nitrite  pro- 

duced. 

13.  Starch  nitrate  broth,  10  days:     No  ammonia  produced;  no  nitrite  pro- 

duced. 

14.  Peptone  nitrite  solution,  10  days :    No  indol  produced. 

15.  Carbohydrate  broths,  12  days:     No  gas  produced.     Per  cent  of  acidity 

(Fuller's    Scale)    with:    Dextrose,   .50;    Lactose,   .20;    Saccharose, 
.10;  Malthose,  .10;  Glycerine,  .10;  Mannite,  .10;  Starch,  .10. 

Bacillus  almus,  n.  sp. 

Source:     Soil  from  Arlington,  CaUfornia;  Bonito,  California,  and  Pasadena,  Cali- 
fornia. 

I.  Morphology. 

1.  Vegetative  cells  :    Average  dimensionsl.2  x  .5  fi. 

2.  Endospores :     None  observed. 

3.  Flagella :     1  to  5  in  number ;  3  to  4  yi^  in  length. 

4.  Staining  reactions:     Gram  negative.     Stains   readily   with  the  aniline 

dyes. 

II.  Cultural  Characteristics. 

5.  Agar  strokes,  5  days. 

Beef  agar:     Scant,  white  to  grayish  white  growth.     On  slopes  from  10 

to  15  days  old  the  growth  becomes  yellowish  white. 
Potato  agar:     Moderate,  glistening,  grayish  white  growth.     After  10 

days,  the  growth  becomes  yellowish. 
Peptone   starch    agar:      Moderate,    glistening,    grayish    white    growth, 

which  becomes  yellowish  on  old  slopes. 

6.  Potato  cylinders:     No  growth  in  30  days. 

7.  Gelatin  stab:     Scant  growth  at  surface  and  along  track  of  the  needle, 

in  5  days.    No  liquefaction  in  30  days. 

8.  Beef  broth,  5  days.    Lightly  clouded. 

9.  Litmus  milk:    Reddened  in  6  days;  neither  coagulated  nor  digested  in 

30  days. 
10.    Plate  cultures. 

Ammonia  cellulose  agar,  15  days. 
Form :    Round. 

Size :    4  to  6  mm.  in  15  days ;  6  to  8  mm.  in  30  days. 
Enzymic  zone :    1  to  1.5  mm.  in  15  days ;  in  25  days  3  to  4  mm. 
Elevation:     Saucer  shaped. 


THE  DECOMPOSITION  OF  CELLULOSE  IN  SOILS  447 

Chromogenesis :     Semi-transparent,  grayish  white  after  15  days ; 

older  colonies  become  yellowish  white  with  a  narrow  grayish 

white  rim. 
Internal  structure :     Colony  is  made  up  of  fine  loosely  arranged 

granules.     The  rim  of  the  older  colonies  is  composed  of  large 
granules  compactly  arranged. 
Edge :     Entire. 
Peptone  cellulose  agar,  15  days. 

Form  :     Round  or  irregularly  round. 

Size :    5  to  7  mm.  in  15  days ;  in  25  days  colonies  frequently  attain 

a  diameter  of  20  mm. 
Enzymic  zone :    2  mm.  in  15  days ;  2.5  to  3.5  mm.  in  30  days. 
Elevation:     Saucer  shaped. 
Chromogenesis :    Central  portion  of  colony  2  to  3  mm.  in  diameter 

is  semi-transparent,  grayish  white ;  outer  portion  of  colony  is 

vitreous.    The  colony  is  usually  surrounded  by  a  narrow  white 

rim. 
Internal  structure :     Central  portion  of  colony  is  granular ;  struc- 
ture of  the  vitreous  portion  is  indeterminate. 
Edge  :    Entire  to  undulate. 
Peptone  starch  agar,  5  days. 

Form :     Irregular.     Those  colonies  at  the  immediate  surface  are 

round  or  nearly  round,  but  those  beneath  the  surface  and  the 

bottom  colonies  are  quite  irregular  in  outline. 
Size :    2  to  3  mm. 
Enzymic  zone :     3  to  4  mm. 
Elevation :     Flat  or  very  slightly  convex. 
Chromogenesis :    The  surface  colonies  show  a  small  white  nucleus, 

the  remainder  of  the  colony  grayish  white.    The  imbedded  and 

bottom  colonies  are  grayish  to  grayish  white. 
Internal  structure :     Granular. 
Edge :     Lacerate. 
Beef  agar,  5  days. 
Form :    Round. 

Size:    Surface  colonies  1  to  1.5  mm. ;  bottom  colonies  2  to  3  mm. 
Elevation :     Convex. 
Consistency :     Colony  is  soft  during  the  first  10  days,  after  which 

it  becomes  brittle. 
Chromogenesis :     By  reflected  light  the  colonies  are  white  to  light 

grayish  white.     By  transmitted  light  they  are  translucent  light, 

smoky  brown. 
Structure :     Granular. 
Edge :    Entire. 
Potato  agar,  5  days. 
Form :    Round. 

Size:     Surface  colonics,  1  to  2  mm. ;  bottom  colonies,  2  to  3  mm. 
Elevation :     Pulvinate. 
Consistency :     Butyrous  after  5  days ;  somewhat  viscous  after  10 

days. 
Chromogenesis :     Glistening,  yellowish  to  grayish  white. 
Internal  structure:     Granular. 
Edge :    Entire. 


448  SOIL  SCIENCE 

11.  Filter  paper  broths,  15  daj's.     Paper  reduced  to  a  loose,  felt-like  mass 

which  retains  the  pure  white  color  of  the  paper.  The  structure  of 
the  paper  has  been  entirely  destroyed,  as  can  be  easily  demon- 
strated by  the  slight  agitation  of  the  solution.  The  decomposition 
of  the  paper  was  less  rapid  with  casein  or  potassium  nitrate  as  the 
source  of  nitrogen  than  with  peptone  or  ammonium  sulphate. 
III.    Biochemical  Features. 

12.  Dunham's  solution,  10  days :     No  ammonia  produced ;  no  nitrite  pro- 

duced. 

13.  Starch  nitrate  broth,  10  days :     No  ammonia  produced ;  no  nitrite  pro- 

duced. 

14.  Peptone  nitrite  solution,  10  days:    No  indol  produced. 

15.  Carbohydrate  broths,  12  days:     No  gas  produced.    Per  cent  of  acidity 

(Fuller's   Scale)   with:    Dextrose,   1.30;  Lactose,  .80;   Saccharose, 
1.00;  Maltose,  1.20;  Glycerine,  .40;  Mannite,  .00;  Starch,  .60. 

Bacillus  concitatus,  n.  sp. 
Source  :     Soil  from  Barstow,  California ;  Covina,  California  ;  Riverside,  California. 

I.  Morphology. 

1.  Vegetative  cells :     Average  dimensions,  1.2  x  .5  fi. 

2.  Endospores :     None  observed. 

3.  Flagella :    1  to  3  in  number ;  3  to  4  ^^  in  length. 

4.  Staining  reactions :     Gram  negative.     Stains   readily  with  the  aniline 

dyes. 

II,  Cultural  Characteristics. 

5.  Agar  strokes,  5  days. 

Beef  agar:     Abundant,  flat,  moist,  yellowish  white. 

Potato  agar:     Abundant,  raised,  moist,  glistening,   grayish  white;  old 

cultures  become  somewhat  yellowish  white. 
Peptone  starch  agar:     Abundant,  raised,  frequently  somewhat  rugose, 

grayish  white. 

6.  Potato  cylinders:     No  growth  in  30  days. 

7.  Gelatin  stab:     Moderate  growth  at  surface  and  along  stab  in  5  days; 

slight  napiform  liquefaction  after  30  days. 

8.  Beef  broth,  5  days:    Heavily  clouded. 

9.  Litmus  milk:     Reddened  in  4  days;  no  curdling  or  digestion  apparent 

after  30  days. 
10.    Plate  cultures. 

Ammonia  cellulose  agar,  15  days. 

Form :  Surface  colonies  are  round  or  irregularly  round ;  bottom 
colonies  spread  out  into  irregular  somewhat  amoeboid  growths. 

Size :  Surface  colonies  are  from  1  to  5  mm. ;  bottom  colonies  fre- 
quently attain  a  diameter  of  15  mm. 

Enzymic  zone :  Surface  colonies,  1  to  1.5  mm. ;  bottom  colonies 
sometimes  show  no  enzymic  zone,  but  the  colony  is  always 
more  transparent  than  the  surrounding  medium,  showing  that 
some  of  the  cellulose  within  the  colony  has  been  dissolved. 

Elevation :     Flat  or  slightly  depressed. 

Chromogenesis :  Many  of  the  colonies  are  almost  pure  white, 
while  others  show  very  thin  brownish  rings. 

Internal  structure :  Brownish  rings  coarsely  granular ;  remainder 
of  colony  finely  granular. 

Edge :    Entire. 


THE  DECOMPOSITION  OF  CELLULOSE  IN  SOILS  449 

Peptone  cellulose  agar,  15  days. 

Form  :  Surface  colonies  round ;  bottom  colonics  irregularly  round. 
Size:  Surface  colonies,  1  to  2  mm.;  bottom  colonies  12  to  15  mm, 
Enzymic  zone:     Surface  colonies,  2  to  2.5  mm.;  bottom  colonies, 

1  mm.  or  less. 
Elevation :     Flat  or  very  slightly  convex. 
Chromogenesis :     Central  portion  of  colony  opaque  white ;  outer 

portion,     semi-transparent    grayish    white.       Brownish    rings 

sometimes  apparent. 
Internal  structure:     Central  portion  of  colony  coarsely  granular, 

remainder  of  colony  finely  granular. 
Edge :   Usually  entire,  but  some  colonies  throw  out  a  thin  film-like 

growth  beyond  the  enzymic  zone  forming  ear-like  lobes. 
Beef  agar,  5  days. 

Form:    Round  or  irregularly  round. 

Size :     Surface  colonies  2  to  3  mm. ;  bottom  colonies  frequently 

spread  over  a  large  part  of  the  plate. 
Elevation :    Decidedly  convex. 

Consistency:     Soft;  old  colonies  become  sHghtly  viscous. 
Chromogenesis:     White  or  light  grayish  white;   bottom  colonies 

frequently  somewhat  fluorescent. 
Internal  structure :     Granular. 
Edge:     Entire  to  undulate. 
Potato  agar,  5  days. 
Form :    Round. 
Size :     Surface  colonies  2  to  3  mm. ;  bottom  colonies  may  attain  a 

diameter  of  10  mm. 
Elevation :      Distinctly    convex ;    old    colonies    become    somewhat 

umbilicate. 
Consistency :    Soft 
Chromogenesis:     Glistening  grayish  white;  some  colonies  show  a 

white  nucleus  and  rim. 
Internal  structure :     Granular ;  nucleus  is  more  coarsely  granular 

than  remainder  of  colony. 
Edge :     Entire. 

11.  Filter  paper  broths,  15  days.     The  paper  is  reduced  to  a  disintegrated 

fibrous  mass  which  retains  its  pure  white  color.  The  destruction  takes 
place  at  about  the  same  rate  with  ammonium  sulphate,  potassium 
nitrate  or  peptone  as  the  source  of  nitrogen.  With  casein  as  a 
source  of  nitrogen  the  destruction  of  the  paper  is  less  rapid, 

III.    Biochemical  Features. 

12.  Dunham's  solution,  10  days.     No  ammonia  produced;   no  nitrite  pro- 

duced. 

13.  Starch  nitrate  solution,  10  days.     No  ammonia  produced;  nitrite  pro- 

duced. 

14.  Peptone  nitrite  solution,  10  days.     Indol  produced. 

15.  Carbohydrate  broths,  12  days.     No  gas  produced.     Per  cent  of  acidity 

(Fuller's  Scale)  with:  Dextrose,  1.80;  Lactose,  .85;  Saccharose, 
1.30;  Maltose,  1.30;  Glycerine,  .45;  Mannite,  .00;  Starch,  1.35. 


450  SOIL  SCIENCE 

Bacillus  desiduosus,  n,  sp. 
Source:     Soil  from  Covina,  California,  and  Riverside,  California. 

I.  Morphology. 

1.  Vegetative  cells :    Average  dimensions  1  x  .4  yu,- 

2.  Endospores:     None  observed. 

3.  Flagella :     1  to  3  in  number ;  3  to  5  yu,  in  length. 

4.  Staining  reactions :     Gram  negative.     Stains  readily  with  the  aniline 

dyes. 

II.  Cultural  Characteristics. 

5.  Agar  strokes,  5  days. 

Beef  agar:     Scant,  flat,  grayish  white,  filiform  growth. 
Potato  agar:     Moderate,  dry,  cream-colored  growth. 
Peptone  starch  agar:     Abundant,  grayish  white  growth. 

6.  Potato  cylinder:    No  growth  in  30  days. 

7.  Gelatin  stab:     Moderate  grayish  white  growth  at  surface  and  along 

track  of  needle,  in  5  days ;  no  liquefaction  in  30  days. 

8.  Beef  broth,  5  days :    Lightly  clouded. 

9.  Litmus  milk :    Reddened  in  3  days ;  neither  coagulated  nor  digested  in 

30  days. 
10.    Plate  cultures. 

Ammonia  cellulose  agar,  15  days. 

Form :     Irregularly  round. 

Size:  Surface  colonies  are  small,  rarely  becoming  more  than  1.5 
mm.  in  diameter;  bottom  colonies  frequently  attain  a  diameter 
of  12  mm. 

Enzymic  zone :    2  to  2.5  mm.  in  15  days ;  3  to  3.5  mm.  in  25  days. 

Elevation :     Slightly  convex. 

Chromogenesis :  Colony  is  gray  white  with  the  exception  of  a 
small  white  nucleus  and  a  narrow  white  rim. 

Structure :     Granular. 

Edge :    Erose. 
Peptone  cellulose  agar,  15  days. 

Form :    Irregularly  round. 

Size :  Surface  colonies  1  to  2  mm. ;  bottom  colonies  may  attain  a 
diameter  of  25  mm. 

Enzymic  zone :  Surface  colonies  1  to  2  mm. ;  bottom  colonies  fre- 
quently show  no  enzymic  zone  until  after  20  days. 

Elevation :     Slightly  convex. 

Chromogenesis :  Surface  colonies  are  semi-transparent,  yellowish 
white.  After  20  days'  growth  the  surface  and  imbedded  colo- 
nies become  quite  yellowish;  bottom  colonies  remain  grayish 
white. 

Internal  structure :     Granular. 

Edge :    Lobate. 
Peptone  starch  agar,  5  days. 

Form :  Surface  and  bottom  colonies  are  round  or  irregularly 
round ;  imbedded  colonies  are  flaky. 

Size :    1.5  to  2.5  mm, 

Enzymic  zone :     1  to  1.5  mm.  in  5  days ;  2  to  2.5  mm.  in  10  days. 

Elevation :    Flat. 

Chromogenesis  :  Grayish  white ;  some  colonies  show  a  small  white 
nucleus. 


THE  DECOMPOSITION  OF  CELLULOSE  IN  SOILS  451 

Internal  structure :  Coarsely  granular.  The  granules  are  fre- 
quently formed  into  large  granular  clumps. 

Edge  :     Entire  or  undulate. 
Beef  Agar,  5  days. 

Form :  Surface  colonies  round ;  bottom  colonies  spread  out  into 
fern-like  growths. 

Size:    Surface  colonies  1  to  1.5  mm.;  bottom  colonies  12  to  15  mm. 

Elevation :     Slightly  convex. 

Consistency:     Soft;  old  colonies  are  somewhat  viscous. 

Chromogenesis :  By  reflected  light  the  colonies  are  grayish  white ; 
by  transmitted  light  they  appear  as  glistening  semi-transparent 
drops. 

Structure :    Granular. 

Edge :    Entire.  ' 

Potato  agar,  5  days. 

Form :    Round. 

Size:     1  to  1.5  mm. 

Elevation :     Convex. 

Consistency :  Very  soft ;  colony  can  be  caused  to  spread  over  the 
medium  by  shaking  the  plate. 

Chromogenesis :  By  reflected  light  the  colonies  are  grayish  white. 
By  transmitted  hght  they  appear  as  glistening  semi-transparent 
drops. 

Structure :     Granular. 

Edge :     Entire. 

11.  Filter  paper  broths,  15  days.    Paper  is  reduced  to  a  finely  divided  gray 

white  mass   which   readily   separates   into  minute   fibrous   particles 
on  slight  agitation.     The  paper  is  decomposed  rapidly  with  ammo- 
nium sulphate,  potassium  nitrate,  peptone  or  casein  as  the  source 
of  nitrogen. 
III.     Biochemical  Features. 

12.  Dunham's  solution,  10  days.     No  ammonia  formed;  nitrite  formed. 

13.  Starch  nitrate  solution,  10  days.     No  ammonia  formed ;  nitrite  formed. 

14.  Peptone  nitrite  solution,  10  days.    Indol  produced. 

15.  Carbohydrate   broths,   12   days.     No   gas  produced.     Per   cent  of  gas 

(Fuller's   Scale)    with:    Dextrose,   .80;   Lactose,   .10;   Saccharose, 
.00;  Maltose,  .60;  Glycerine,  .00;  Mannite,  .00;  Starch,  .20. 

Bacillus  festinus,  n.  sp. 

Source:     Soil    from    Banning,   California;    Fullerton,    California;    Whittier,   Cali- 
fornia. 
I.    Morphology. 

1.  Vegetative  cells :    Average  dimensions  2  x  .6  ^. 

2.  Endospores:      Form,   elliptical;   size,   average   dimensions   .8   x   .5  y^; 

germination,  equatorial;  rod,  swollen. 

3.  Flagella  :    1  to  3  in  number ;  4  to  6  ^  in  length. 

4.  Staining  reactions:     Gram  negative.     Stains   readily  with  the  aniline 

dyes. 
TI.     Cultural  Characteristics. 

5.  Agar  strokes,  5  days. 

Beef  agar:     Scant,  flat,  grayish  white,  spreading  growth. 


452  SOIL  SCIENCE 

Potato  agar:     Abundant,  grayish  white,  flat  growth,  usually  spreading 

over  the  entire  slope. 
Peptone  starch  agar:     Moderate,  grayish  white  after  5  days,  but  in 

cultures  from  6  to  10  days  old  the  growth  becomes  a  rich  orange. 

The  pigment  diffuses  through  the  medium  very  slowly. 

6.  Potato  cylinders:     No  growth  in  30  days. 

7.  Gelatin  stab:     Scant  growth  at  surface  and  along  track  of  the  needle 

in  10  days.    No  liquefaction  in  30  days. 

8.  Beef  broth:    Not  clouded  in  5  days. 

9.  Litmus  milk:    Reddened  in  3  days;  coagulated  and  digested  in  25  days. 
10.    Plate  cultures. 

Ammonia  cellulose  agar,  15  days. 

Form :    Round. 

Size :  10  to  12  mm.  The  colonies  continue  to  grow  after  15  days, 
and  when  kept  in  a  moist  chamber  for  30  days  the  colonies 
frequently  attain  a  diameter  of  25  mm. 

Enzymic  zone:  In  young  colonies  the  clearing  is  all  within  the 
colony ;  after  30  days  the  enzymic  zone  is  frequently  2  to  3  mm. 

Elevation :     Saucer-shaped. 

Chromogenesis :  The  central  portion  of  the  colony,  usually  6  to 
10  mm.  in  diameter,  is  semi-transparent  grayish  white.  The 
remainder  is  vitreous  with  the  exception  of  a  thin  white  rim. 

Internal  structure:  The  central  portion  of  the  colony  is  made  up 
of  loosely  arranged,  coarse  granules.  The  structure  of  the 
vitreous  zone  is  indeterminate. 

Edge :     Entire. 
Peptone  cellulose  agar,  15  days. 

Form :    Round. 

Size :    5  to  6  mm.  in  15  days ;  10  to  12  mm.  in  30  days. 

Enzymic  zone :    2  to  3  mm. 

Elevation :    Saucer-shaped. 

Chromogenesis :  Central  portion  of  colony  is  transparent  or  semi- 
transparent  grayish  white.  Outer  portion  of  colony  is  semi- 
transparent  yellowish  white.  Colony  is  usually  surrounded  by 
a  thin  yellowish  white  rim. 

Internal  structure :  The  colony  is  composed  of  fine  granules 
loosely  arranged. 

Edge :    Entire. 
Peptone  starch  agar,  5  days. 

Form:  Surface  colonies,  round;  imbedded  and  bottom  colonies 
irregularly  round. 

Size:    15  to  25  mm. 

Enzymic  zone :    2  to  3  mm.  in  5  days ;  3.5  to  4  mm.  in  10  days. 

Elevation :    Flat  or  very  slightly  convex. 

Chromogenesis :  Central  portion  of  colony  is  a  rich  orange,  outer 
portion  grayish  to  yellowish  white. 

Internal  structure :  Consists  of  large  granules  frequently  formed 
into  clumps. 

Edge :    Entire  to  undulate. 
Beef  Agar,  5  days. 

Form :    Round. 

Size :    Surface  colonies  1  mm.  or  less ;  bottom  colonies  3  to  4  mm. 


THE  DECOMPOSITION  OF  CELLULOSE  IN  SOILS  453 

Elevation :     Slightly  convex. 

Consistency :     Butyrous,  old  colonies  become  brittle. 

Chromogenesis :       White     nucleus,     remainder     semi-transparent, 

glistening,  grayish  white. 
Internal    structure :      Finely    granular    with    exception    of    nucleus 

which  is  made  up  of  granular  clumps. 
Potato  agar,  5  days. 

Form:    Round.  ^ 

Size:     Surface  colonies  2  to  3  mm.;  bottom  colonies  4  to  5  mm. 
Elevation :      Convex ;    old   colonies    frequently    become    somewhat 

umbilicate. 
Consistency :     Butyrous. 
Chromogenesis :     Grayish  to  yellowish   white.     Sometimes   shows 

brownish  rings. 
Internal  structure:     Finely  granular. 
Edge :    Entire. 

11.  Filter  paper  broths,  15  days.    Paper  is  very  completely  disintegrated  into 

a  grayish  white  felt-like  mass,  which  readily  separates  into 
minute  fibrous  particles  on  slight  agitation.  The  paper  undergoes 
rapid  decomposition  when  the  nutrient  solution  contains  inorganic 
nitrogen  in  the  form  of  ammonium  sulphate  or  potassium  nitrate, 
and  also  when  organic  nitrogen  is  added  in  the  form  of  peptone 
or  casein. 
III.    Biochemical  Features. 

12.  Dunham's  solution,  10  days.     No  ammonia  produced ;   no  nitrite  pro- 

duced. 

13.  Starch  nitrate  solution,  10  days.     No  ammonia  produced;  nitrite  pro- 

duced. 

14.  Peptone  nitrite  solution,  10  days.     Indol  produced. 

15.  Carbohydrate  broths,  12  days.     No  gas  produced.    Per  cent  of  acidity 

(Fuller's   Scale)    with:     Dextrose,   .50;    Lactose,   .40;    Saccharose, 
.00;  Maltose,  .65;  Glycerine,  .05;  Mannite,  .00;  Starch,  .60. 

Bacillus  gihus,  n.  sp. 

Source:     Soil  from  Azusa,  California;  Chula  Vista,  California;  Davis,  California; 
Porterville,  California ;  and  Riverside,  California. 

I.  Morphology. 

1.  Vegetative  cells:     Average  dimensions  1.5  x  .5  fx. 

2.  Endospores :    None  observed. 

3.  Flagella :     1  to  4  in  number ;  4  to  6  y^t  in  length. 

4.  Staining   reactions :     Gram    negative.      Stains   readily   with   the  aniline 

dyes. 

II.  Cultural  Characteristics. 

5.  Agar  strokes,  5  days. 

Beef  agar:     Scant,  yellowish  white,  filiform  growth. 

Potato  agar:     Abundant,  canary  yellow,  growth  spreading  over  a  large 

part  of  the  slope. 
Peptone    starch    agar:      Abundant,    grayish    white,    glistening    growth 

which  becomes  somewhat  yellowish  after  10  days. 

6.  Potato  cylinders:     Abundant  canary  yellow  in  5  days. 

7.  Gelatin  stab:     Moderate  yellowish  w'hite  growth  at  surface  and  along 

track  of  needle  in  10  days ;  no  liquefaction  in  30  days. 
(32) 


454  SOIL  SCIENCE 

8.  Beef  broth,  5  days :     Slightly  clouded. 

9.  Litmus  milk:     Reddened  in  6  days;  neither  coagulated  nor  digested  in 

30  days. 
10.    Plate  cultures. 

Ammonia  cellulose  agar,  15  days. 

Form :    Round  to  irregularly  round. 

Size :    2  to  3  mm. 

Enzymic  zone :  Entire  colony  semi-transparent ;  enzymic  zone  not 
more  than  1  mm. 

Elevation :     Flat  or  slightly  depressed. 

Chromogenesis :  Semi-transparent,  grayish  white,  usually  show- 
ing a  small  white  nucleus. 

Internal  structure:    Granular. 

Edge :     Entire  to  undulate. 
Peptone  cellulose  agar,  15  days. 

Form :    Round. 

Size :    2  to  4  mm. 

Enzymic  zone:     1.5  to  2  mm.  in  15  days;  3  to  4  mm.  in  25  days. 

Elevation :     Slightly  concave. 

Chromogenesis :  Grayish  white,  frequently  showing  a  small  white 
nucleus,  usually  forms  a  thin  grayish  white  semi-transparent 
rim  beyond  the  enzymic  zone. 

Internal  structure :     Granular. 

Edge :     Entire. 
Peptone  starch  agar,  5  days. 

Form :    Round  to  irregularly  round. 

Size :    2  to  3  mm. 

Enzymic  zone :     1  to  1.5  mm. 

Elevation :     Slightly  convex. 

Consistency :     Soft,  becoming  brittle  after  10  days. 

Chromogenesis :  Grayish  to  yellowish  white.  After  10  days  the 
colonies  become  quite  yellowish. 

Internal  structure :     Granular. 

Edge  :     Entire  to  undulate. 
Beef  Agar,  5  days. 

Form :     Round. 

Size :     Surface  colonies  1  to  2  mm. ;  bottom  colonies  3  to  3.5  mm. 

Elevation :     Convex. 

Consistency :     Soft. 

Chromogenesis :  After  3  days  the  colonies  are  grayish  to  yellow- 
ish white ;  the  yellow  color  increases  with  the  age  of  the 
colony  and  after  10  days  they  are  distinctly  yellow. 

Internal  structure:  Coarsely  granular.  The  granules  are  fre- 
quently formed  into  clumps. 

Edge :     Entire. 
Potato  agar,  5  days. 

Form :     Round. 

Size :    2  to  3  mm. 

Elevation :    Convex. 

Consistency :     Butyrous. 

Chromogenesis :  Canary  yellow ;  some  colonies  show  brownish 
rings. 

Internal  structure:    Granular. 

Edge :    Entire. 


THE  DECOMPOSITION  OF  CELLULOSE  IN  SOILS  455 

11.  Filter  paper  broths,   15  days.     The  paper  is  reduced  to  a  thin  white 

filmy  mass  which  breaks  up  into  minute  particles  on  slight  agita- 
tion.    The  decomposition  of  the  paper  proceeds  rapidly  with  am- 
monium   sulphate,    potassium    nitrate,    peptone    or    casein    as    the 
source  of  nitrogen. 
Ill,    Biochemical  Features. 

12.  Dunham's  solution,  10  days.    Ammonia  formed ;  nitrite  formed. 

13.  Starch  nitrate  solution,  10  days.    No  ammonia  formed ;  nitrite  formed. 

14.  Peptone  nitrite  solution,  10  days.     Indol  formed. 

15.  Carbohydrate  broths,  12  daj's.     No  gas  produced.     Per  cent  of  acidity 

(Fuller's  Scale)  with:  Dextrose,  1.20;  Lactose,  .75;  Saccharose, 
.80;  Maltose,  1.00;  Glycerine,  .40;  Mannite,  .00;  Starch,  1.00. 

Bacillus  imminutus,  n.  sp. 

Source  :     Soil  from  Highland,  California ;  Berkeley,  California ;  Corona,  Califor- 
.    nia;    Redlands,    California;    Whittier,    California;    Santa    Paula,    California; 
Pasadena,    California;    Azusa,    California;    Fullerton,    California;    Porterville, 
California. 

I,  Morphology. 

1.  Vegetative  cells :    Average  dimensions  1.5  x  .2  fi.    The  vegetative  cells 

pass  quickly  into  involution  forms  which  frequently  attain  a  length 
of  from  6  to  8  ^  without  increasing  in  thickness.     The  involution 
forms  are  commonly  curved  cells,   frequently  more  or  less   fusi- 
form. 

2.  Endospores :      Form,    round;    average    size,    .5    fi]    germination,    polar. 

Rod  is  swollen  during  germination,  giving  the  cell  a  drumstick 
appearance.  On  cellulose  agar  the  spores  appear  in  from  4  to  6 
days. 

3.  Flagella :     1  to  5  in  number ;  3  to  5  fi  in  length. 

4.  Staining  reactions :     Gram  negative.     Stains  readily   with   the  aniline 

dyes. 

II.  Cultural  Characteristics. 

5.  Agar  strokes,  5  days. 
Beef  agar:     No  growth. 

Potato  agar:     No  growth.  '  ' 

Peptone  starch  agar:    No  growth. 

6.  Potato  cylinders:     No  growth  in  30  days. 

7.  Gelatine  stab:     No  growth  in  30  days. 

8.  Beef  broth,  5  days :    No  growth. 

9.  Litmus  milk:     No  growth  in  30  days. 
10.    Plate  cultures. 

Ammonia  cellulose  agar,  15  days. 

Form :    Round. 

Size :  The  size  of  the  colonies  is  quite  variable ;  after  15  days 
the  diameter  is  usually  between  12  and  15  mm.  The  colony 
continues  to  increase  in  size  as  long  as  the  medium  remains 
moist,  and  where  plates  can  be  kept  free  from  molds  a  single 
colony  may  eventually  cover  the  entire  plate.  The  round  form 
of  the  colony  is  maintained  as  long  as  the  growth  is  unob- 
structed. 


456  SOIL  SCIENCE 

Enzymic  zone :  The  entire  colony  is  transparent.  The  enzyme 
does  not  clear  the  cellulose  beyond  the  development  of  the 
colony. 

Elevation :  Young  colonies  are  saucer-shaped.  As  the  colony 
spreads  the  depression  is  less  apparent. 

Chromogenesis  :  Vitreous.  Some  colonies  show  a  very  narrow  white 
rim.  Old  colonies  frequently  become  a  light  transparent  yel- 
low. 

Internal  structure :     Granular. 

Edge :    Entire. 
Peptone  cellulose  agar,  15  days. 

Form :    Round. 

Size :  10  to  12  mm.  in  15  days ;  colonies  continue  to  grow  as  long 
as  the  medium  is  kept  moist.  When  the  plate  contains  only  a 
very  few  colonies  the  diameter  may  be  50  mm.  or  more  in  30 
days. 

Enzymic  zone :  The  entire  colony  is  transparent  with  the  excep- 
tion of  a  very  narrow  white  rim.  The  enzyme  does  not 
spread  beyond  the  development  of  the  colony. 

Elevation :  The  young  colonies  are  distinctly  concave.  As  the 
colony  becomes  older  the  depression  is  less  apparent. 

Chromogenesis :  Vitreous.  Some  colonies  show  a  very  narrow 
white  rim.  Old  colonies  frequently  become  a  light  trasparent 
yellow. 

Internal  structure :  Indeterminate  with  the  exception  of  the  nar- 
row white  rim  which  is  granular. 

Edge :     Entire. 
Peptone  starch  agar:     No  colonies  produced  in  10  days. 
Beef  agar:     No  colonies  produced  in  10  days. 
Potato  agar:     No  colonies  produced  in  10  days. 

11.  Filter  paper  broths,  15  days. "  The  paper  is  reduced  to  a  very  thin  yel- 

lowish filmy  mass,  which  disintegrates  on  very  slight  agitation. 
The  paper  is  destroyed  at  about  the  same  rate  with  ammonium 
sulphate,  potassium  nitrate  or  peptone  as  the  source  of  nitrogen. 
A  slower  destruction  of  the  paper  occurs  when  nitrogen  is  sup- 
plied in  the  form  of  casein. 
III.    Biochemical  Features. 

12.  Dunham's  solution,  10  days.     No  ammonia  produced ;   no  nitrite  pro- 

duced. 

13.  Starch  nitrate  solution,  10  days.    No  ammonia  produced ;  no  nitrite  pro- 

duced. 

14.  Peptone  nitrite  solution,  10  days.    No  indol  produced. 

15.  Carbohydrate  broths,  12  days.     No  gas  produced.     Per  cent  of  acidity 

(Fuller's  Scale)   with:    Dextrose,  0.00;  Lactose,  0.00;  Saccharose, 
0.00 ;  Maltose,  0.00 ;  Glycerine,  0.00 ;  Mannite,  0.00 ;  Starch,  0.00. 

Bacillus  iugis,  n.  sp. 

Source  :     Soil  from  Lordsburg,  California ;   Redlands,  California ;  and  San  Fer- 
nando, California.  ' 
I,    Morphology. 

1.  Vegetative  cells :    Average  dimensions  1.4  x  .4  ^. 

2.  Endospores :     None  observed. 


THE  DECOMPOSITION  OF  CELLULOSE  IN  SOILS  457 

3.  Flagella  :    1  to  3  in  number ;  3  to  4  ^  in  length. 

4.  Staining  reactions :     Gram   negative.     Stains   readily   with   the  aniline 

dyes. 
II.    Cultural  Characteristics. 

5.  Agar  strokes,  5  days. 

Beef  agar:     Scant,  grayish  white,  filiform  growth. 
^  Potato  agar:     Abundant,  glistening,  grayish  white,  filiform  growth. 

Peptone  starch  agar:     Moderate,  grayish  while,  filiform  growth. 

6.  Potato   cylinders,  30  days :     Scant,   glistening,   colorless   growth  when 

very  heavily  inoculated.     Light  inoculation  produces  no  growth. 

7.  Gelatin  ,stab:     Moderate  growth  at  surface  and  along  track  of  needle 

in  5  days ;  napiform  liquefaction  in  30  days. 

8.  Beef  broth,  5  days  :     Heavily  clouded. 

9.  Litmus  milk:     Reddened  in  5  days;  neither  coagulated  nor  digested  in 

30  days. 
10.    Plate  cultures. 

Ammonia  cellulose  agar,  IS  days. 

Form :    Round. 

Size :    1.5  to  2.5  mm.  in  15  days ;  3  to  3.5  mm.  in  25  days. 

Enzymic  zone :  Clearing  sometimes  all  within  colony  after  15 
days.  After  20  days  all  colonies  show  an  enzymic  zone  of 
1  mm.  or  more. 

Elevation :     Flat. 

Chromogenesis :  Semi-transparent,  light  grayish  white ;  some- 
times contoured  by  light  whitish  lines. 

Internal  structure:     Granular. 

Edge :     Entire. 
Peptone  cellulose  agar,  15  days. 

Form :     Irregularly  round. 

Size :    5  to  8  mm.  in  15  days ;  no  increase  in  size  after  15  days. 

Enzymic  zone :  2  to  3  mm.  The  zone  continues  to  increase  in 
width  up  to  30  days,  in  which  time  it  is  frequently  5  mm. 

Elevation :     Slightly  convex. 

Chromogenesis :  Central  portion  of  colony  is  white ;  the  outer  por- 
tion gray-white ;  sometimes  forms  a  white  nucleus  and  rim. 

Internal  structure :  Central  portion  of  colony  coarsely  granular, 
outer  portion  finely  granular. 

Edge:    Undulate  to  lobate. 
Peptone  starch  agar,  5  days. 

Form  :     Irregularly  round. 

Size:    1.5  to  2  mm.  in  15  days;  2.5  mm.  in  25  days. 

Enzymic  zone:    1  nam.  or  less. 

Elevation:  Capitate.  (The  colonies  on  starch  agar  are  raised  in 
a  characteristic  jelly-like  mass.) 

Consistency :     Gelatinous. 

Chromogenesis :    Grayish  white. 

Internal  structure :    Fine  granules  loosely  arranged. 

Edge :    Lancelate. 
Beef  agar,  5  days. 

Form  :     Surface  colonies  round ;  imbedded  colonies,  lenticular. 

Size:    1.5  to  2  mm. 

Elevation :     Convex. 


SOIL  SCIENCE 

Consistency :     Soft ;  old  colonies  become  somewhat  gelatinous. 
Chromogenesis :     Small  white  nucleus,  remainder  semi-transparent 

grayish  white. 
Internal  structure:    Granular. 
Edge :     Entire. 
Potato  agar,  5  days. 

Form :      Surface    colonies,    round ;    bottom    colonies,    irregularly 

round. 
Size :    Surface  colonies  1  to  1.5  mm. ;  bottom  colonies  2.5  to  4  nun. 
Elevation :     Convex. 
Consistency :     Soft. 

Chromogenesis :    Grayish  white,  with  a  pearl-like  luster. 
Internal  structure :     Granular. 
Edge :     Entire. 

11.  Filter  paper  broths,  15  days.     The  paper  retains  something  of  its  origi- 

nal structure ;  but  shows  many  ragged  holes  where  the  fibers  have 
been  dissolved  away.  Very  slight  agitation  is  sufficient  to  disinte- 
grate the  paper  mass  completely.  The  decomposition  takes  place 
at  about  the  same  rate  with  ammonium  sulphate  or  peptone  as  the 
source  of  nitrogen.  The  decomposition  was  much  slower  when 
casein  or  potassium  nitrate  was  used. 
III.    Biochemical  Features. 

12.  Dunham's  solution,  10  days.     Ammonia  produced ;  nitrite  produced. 

13.  Starch  nitrate  solution,  10  days.     No  ammonia  produced ;  nitrite  pro- 

duced. 

14.  Peptone  nitrite  solution,  10  days.    No  indol  produced. 

15.  Carbohydrate  broths,  12  days.     No  gas  produced.     Per  cent  of  acidity 

(Fuller's  Scale)    with:    Dextrose,  .80;  Lactose,   1.10;   Saccharose, 
1.60;  Maltose,  1.55;  Glycerine,  .45;  Mannite,  .20;  Starch,  1.50. 

Bacterium  castigatum,  n.  sp. 

Source  :      Soil    from    Banning,    California ;    Glendora,    California ;    and   Wineville, 
California. 

I.  Morphology. 

1.  Vegetative  cells:     Average  dimensions  1.2  x  .4  fi. 

2.  Endospores :     None  observed. 

3.  Staining  reactions :     Gram   negative.     Stains   readily  with  the  aniline 

dyes. 

II.  Cultural  Characteristics. 

4.  Agar  strokes,  5  days. 

Beef  agar:    Abundant,  moist,  glistening,  grayish  white  growth. 

Potato  agar:     Abundant,  glistening,  grayish  white;  becomes  yellowish 

white  after  10  days. 
Peptone  starch  agar:    Abundant,  raised,  somewhat  rugose. 

5.  Potato  cylinders,  30  days :    No  growth. 

6.  Gelatin  stab:     Moderate  growth  at  surface  and  along  track  of  needle 

in  6  days ;  no  liquefaction  after  30  days. 

7.  Beef  broth,  5  days :    Lightly  clouded. 

8.  Litmus  milk:     Reddened  in  3  days;  neither  coagulated  nor  digested  in 

30  days. 


THE  DECOMPOSITION  OF  CELLULOSE  IN  SOILS  459 

Plate  cultures. 

Ammonia  cellulose  agar,  15  days. 
Form :     Irregularly  round. 
Size:     1  to  1.5  mm. 
Enzymic  zone:     1  to  1.5  mm.;  in  30  days  the  enzymic  zone  may 

attain  a  diameter  of  2.5  mm. 
Elevation :     Slightly  convex. 

Chromogenesis :     Opaque  white  or  light  grayish  white. 
Internal  structure:     Granular. 
Edge :    Undulate. 
Peptone  cellulose  agar,  15  days. 
Form  :     Irregularly  round. 
Size:     1  to  1.5  mm. 
Enzymic  zone :     .5  to  1  mm. ;  in  30  days  the  enzymic  zone  may 

reach  a  diameter  of  2  mm. 
Elevation :     Slightly  convex. 
Chromogenesis:      White   nucleus    and    rim,    remainder    of    colony 

grayish  white. 
Internal  structure:     Nucleus  and  rim  made  up  of  coarse  compact 

granules,  remainder  of  colony  finely  granular. 
Edge :     Undulate. 
Peptone  starch  agar,  5  days. 
Form :     Irregularly  round. 
Size:     7  to  10  mm. 

Enzymic  zone:     1  to  1.5  mm.  in  5  days;  2.5  to  3  mm.  in  10  days. 
Elevation :     Flat  or  slightly  convex. 
Consistency :     Firm. 
Chromogenesis:     Grayish  white  cottony-like  colony  in  5  days;  in 

10  days  colonies  become  distinctly  grayish. 
Internal  structure:     Coarsely  granular. 
Edge :     Lancelate. 
Beef  agar,  5  daj's. 
Form :     Round. 

Size :     Surf  :ice  colonies  1  to  1.5  mm. ;  bottom  colonies  2  to  3  mm. 
Elevation :     Slightly  convex. 

Consistency :    After  5  days  colonies  are  soft ;  after  10  days,  brittle. 
Chromogenesis:      Very    small    white    nucleus,    remainder    of 
colony   grayish   white.      Surface   colonies   exhibit   a   pearl-like 
luster. 
Internal  structure:     Granular. 
Edge :     Entire. 
Potato  agar,  5  days. 

Form  :     Surface  colonies  round ;  bottom  colonies  irregularly  round. 
Size :     Surface  colonies  1  to  2  mm. ;  bottom  colonies  2  to  3  mm. 
Elevation :     Convex. 
Consistency:     After  5  days  colonies  are  soft;  after  10  days,  buty- 

rous. 
Chromogenesis:      Light   grayish    white,    semi-transparent   colonies 

with  a  pearl-like  luster. 
Internal  structure:    Made  up  of  fine  granules,  loosely  arranged. 
Edge :    Entire. 


460  SOIL  SCIENCE 

10.  Filter  paper  broths,  15  days.    Paper  very  completely  disintegrated  and 

reduced  to  a  pulp-like  mass  which  settles  to  the  bottom  of  the 
flask.  The  paper  is  vigorously  attacked  in  solutions  containing 
ammonium  sulphate,  potassium  nitrate,  or  peptone  as  the  source  of 
nitrogen.  Casein  appeared  to  be  less  favorable  for  the  rapid  devel- 
opment of  this  organism. 
III.    Biochemical  Features. 

11.  Dunham's  solution,  10  days.    No  ammonia  formed ;  nitrite  formed. 

12.  Starch  nitrate  broth,  10  days.    No  ammonia  formed ;  no  nitrite  formed. 

13.  Peptone  nitrite  broth,  10  days.    No  indol  produced. 

14.  Carbohydrate  broths.     No  gas  produced.     Per  cent  of  acidity  (Fuller's 

Scale)    with:     Dextrose,    1.50;    Lactose,    1.10;    Saccharose,    1.00; 
Maltose,  1.45 ;  Glycerine,  .55 ;  Mannite,  .00 ;  Starch,  1.40. 

Bacterium  idoneum,  n.  sp. 

Source  :     Soil  from  Mentone,  California ;  and  Whittier,  California. 

I.  Morphology. 

1.  Vegetative  cells :     Average  dimensions  1.5  to  .5  ^. 

2.  Endospores :     None  observed. 

3.  Staining   reactions :     Gram  negative.     Stains   readily  with  the  aniline 

dyes. 

II.  Cultural  Characteristics. 

4.  Agar  strokes,  5  days. 

Beef  agar:     Scant,  yellowish  white,  glistening,  filiform  growth;  in  10 

days  growth  becomes   distinctly  yellowish. 
Potato  agar:     Abundant,  moist,  glistening,  faint  yellowish  to  glistening 

white ;  becomes  distinctly  yellowish  in  10  days. 
Peptone  starch  agar:     Moderate,  flat,  white,  filiform  growth;  becomes 

faintly  yellowish  in  10  days. 

5.  Potato   cylinders:     Abundant,  moist,   glistening,  grayish  white  growth 

in  IS  days. 

6.  Gelatin  stab:     Moderate,  yellowish  growth  at  surface  and  along  track 

of  needle  in  10  days.     SHght  napiform  liquefaction  after  30  days. 

7.  Beef  broth,  5  days :     Turbid. 

8.  Litmus  milk :     Reddened  in  3  days ;  neither  coagulated  nor  digested  in 

30  days. 

9.  Plate  cultures. 

Ammonia  cellulose  agar,  15-  days. 

Form :     Irregularly  round. 

Size:    1  to  1.5  mm. 

Enzymic  zone:     1  mm.  or  less  after  15  days;  after  30  days  the 
enzymic  zone  has  attained  a  diameter  of  2  to  3  mm. 

Elevation :    Flat. 

Chromogenesis :     Opaque  white  or  light  grayish  white. 

Internal  structure :    The  colony  is  made  up  of  rather  coarse  gran- 
ules compactly  arranged. 

Edge :    Lobate. 
Peptone  cellulose  agar,  15  days. 

Form :     Irregularly  round. 

Size :     1  to  1.5  mm. ;  maximum  development  is  reached  in  15  days. 

Enzymic  zone:     .5  to  1.0  mm.  in  15  days;  1.5  to  2  mm.  after  30 
days. 

Elevation :    Flat. 


THE  DECOMPOSITION  OF  CELLULOSE  IN  SOILS  461 

Chromogenesis :     Opaque  white  to  light  grayish  white. 

Internal  structure :    Coarse  granules,  compactly  arranged. 

Edge :    Lobate. 
Peptone  starch  agar,  5  days. 

Form :     Irregularly  round. 

Size :    1  to  2  mm. 

Enzymic  zone:    1  to  1.5  mm.  in  5  days;  2  to  2.5  mm.  in  10  days. 

Elevation  :     Convex ;  frequently  somewhat  pulvinate. 

Consistency :     After  5  days  the  colonies  are  soft ;  older  colonies 
become  somewhat  viscous. 

Internal    structure :      Granular ;    granules    frequently    arranged   in 
clumps. 

Edge :    Lobate. 
Beef  agar,  5  days. 

Form :     Round. 

Size:     Surface  colonies  1  to  1.5  mm.;  bottom  colonies  2  to  3  mm. 

Elevation :     Convex. 

Consistency:     Soft;  becomes  brittle  after  10  days. 

Chromogenesis:     Grayish  white  pearl-like  luster.     By  transmitted 

light  the  colonies  appear  as  semi-transparent  glistening  drops. 

Internal  structure:     Granular. 

Edge :     Entire. 
Potato  agar,  5  days. 

Form  :     Surface  colonies,  round ;  imbedded  and  bottom  colonies, 
irregularly  round. 

Size  :    2  to  3  mm. 

Elevation :    Pulvinate. 

Consistency:     After  5  days  colonies  are  soft;  after  10  days,  buty- 
rous  or  brittle. 

Chromogenesis:     Reflected  light,  yellowish  to  grayish  white;  trans- 
mitted Hght,  semi-transparent  glistening  drops. 

Internal  structure :     Coarsely  granular. 

Edge :     Entire. 

10.  Filter  paper  broths,  15  days.     Paper  is  reduced  to  a  thin  limp  sheet 

which  falls  apart  on  slight  agitation.  Solutions  containing  ammo- 
nium sulphate,  potassium  nitrate  and  peptone  as  the  source  of 
nitrogen  show  a  rapid  decomposition  of  the  paper.  Solutions  con- 
taining casein  showed  only  a  slight  decomposition  of  the  paper 
even  after  30  days'  incubation. 
III.    Biochemical  Features. 

11.  Dunham's  solution,  10  days.    No  ammonia  formed;  nitrite  formed. 

12.  Starch  nitrate  broth,  10  days.    No  ammonia  produced;  nitrite  produced. 

13.  Peptone  nitrite  solution,  10  days.     No  indol  produced. 

14.  Carbohydrate  broths,  12  days.     No  gas  produced.     Per  cent  of  acidity 

(Fuller's    Scale)    with:    Dextrose,    1.60;    Lactose,    1.20;    Maltose, 
1.40;  Mannite,  .00;   Saccharose,  1.30;  Glycerine,  .70;   Starch,  1.40. 

Bacterium  hicrosum,  n.  sp. 

Source:     Soil  from  Redlands,  California;  and  Upland,  California. 
I.    Morphology. 

1.  Vegetative  cells:     Average  dimensions  1.3.  x  .4  p,. 

2.  Endospores :    None  observed. 


462  SOIL  SCIENCE 

3.  Staining  reactions :     Gram   negative.     Stains  readily  with  the  aniline 

dyes, 
II.    Cultural  Characteristics. 

4.  Agar  strokes,  5  days. 

Beef  agar:  Moderate,  flat,  grayish  white;  old  cultures  become  some- 
what irridescent. 

Potato  agar:  Moderate,  dirt}'  yellowish  white  in  5  days;  becomes 
more  yellowish  with  age. 

Peptone  starch  agar:  Abundant,  moist,  grayish  white  in  5  days;  be- 
comes faintly  yellowish  in  10  days. 

5.  Potato  cylinder,  30  days :     No  growth. 

6.  Gelatin  stab:     No  growth  after  30  days. 

7.  Beef  broth,  5  days :    Heavily  clouded. 

8.  Litmus  milk:     No  change  in  milk  in  30  days. 

9.  Plate  cultures. 

Ammonia  cellulose  agar,  15  days. 

Form :     Irregularly  round. 

Size:  15  to  20  mm.;  in  30  days  the  colonies  frequentlj'  reach  a 
diameter  of  25  to  30  mm. 

Enzymic  zone :  When  there  are  only  a  few  colonies  on  the  plate, 
permitting  rapid  spreading,  the  clearing  is  all  within  the 
colony  until  after  30  daj^s,  when  an  enzymic  zone  usually  de- 
velops. On  crowded  plates  the  colonies  always  show  an  enzy- 
mic zone  of  1  mm.  or  more. 

Elevation :     Slightly  concave. 

Chromogenesis :  Central  portion  of  colony,  usually  6  to  19  mm. 
in  diameter,  is  grayish  white;  outer  portion  of  colony  is  vitre- 
ous. The  vitreous  zone  is  usually  surrounded  by  a  thin  white 
rim. 

Internal  structure :  Colony  is  made  up  of  medium-sized,  loosely 
arranged  granules. 

Edge :     Undulate. 
Peptone  cellulose  agar,  15  days. 

Form :     Round. 

Size :    2  to  3  mm.  in  15  days ;  3  to  4  mm.  in  25  days. 
'  Enzymic  zone:     1  to  1.5  mm.  in  15  days;  2  to  3  mm.  in  25  days. 

Elevation :     Flat. 

Chromogenesis :  Nucleus  and  rim  are  white,  remainder  of  colony 
semi-transparent  grayish  white. 

Internal  structure :     Granular. 

Edge :     Entire. 
Peptone  starch  agar,  5  days. 

Form :     Irregularly  round. 

Size :    3  to  4  mm. 

Enzymic  zone :     .5  to  1  mm.  in  5  days ;  2  to  3  mm.  in  10  days. 

Elevation :     Convex. 

Consistency :     Soft ;  after  10  days  colonies  become  brittle. 

Chromogenesis :  Central  portion  of  colony  semi-transparent, 
glistening  white ;  outer  portion  vitreous. 

Internal  structure :     Granular. 

Edge :    Undulate. 


THE  DECOMPOSITION  OF  CELLULOSE  IN  SOILS  463 

'  Beef  agar,  5  days. 

Form :     Surface   colonies,   round ;    imbedded  colonies,  lenticular ; 
bottom  colonies,  irregularly  round. 

Size :     1  to  1.5  mm. 

Elevation :     Slightly  convex. 

Consistency :     Soft ;  in  10  days  growth  becomes  somewhat  gelatin- 
ous. 

Chromogenesis :     Very  small  white  nucleus ;  remainder  of  colony 
semi-transparent  grayish  white. 

Internal  structure :     Granular. 

Edge :     Entire. 
Potato  agar,  5  days. 

Form  :     Surface  colonies,  round ;  bottom  and  imbedded  colonies, 
irregularly  round. 

Size:     1.5  to  2  mm. 

Elevation :    Convex. 

Consistency :     Butyrous  after  5  days ;   somewhat  gelatinous  after 
10  days. 

Chromogenesis:     Yellowish  to  grayish  white;  after  10  days  colo- 
nies become  quite  yellowish. 

Internal   structure :     Coarsely  granular.     Some  colonies  are  gru- 
mose. 

Edge :     Entire. 

10.  Filter  paper  broths,  15  days.     Paper  is  reduced  to  pulpy  grayish  white 

mass  consisting  of  very  short  fibers  which  separate  on  slight  agi- 
tation.    The  paper  is  decomposed  rapidly  in  the  ammonium  sul- 
phate and  peptone  broths,  but  more  slowly  in  the  broths  contain- 
ing casein  or  potassium  nitrate. 
III.    Biochemical  Characteristics. 

11.  Dunham's  solution,  10  days.     No  ammonia  produced ;  nitrite  produced. 

12.  Starch  nitrate  solution,  10  days.    No  ammonia  produced ;  no  nitrite  pro- 

duced. 

13.  Peptone  nitrite  solution,  10  days.     No  indol  produced. 

14.  Carbohydrate  broths.     No  gas  produced.     Per  cent  of  acidity  (Fuller's 

Scale)   with:    Dextrose,  .20;  Lactose,  .10;   Saccharose,  .00;  Malt- 
ose, .15;  Glycerine,  .00;  Mannite,  .05;  Starch,  .15. 

Bacterium  paludosum,  n.  sp. 

Source:     Soil  from  Berkeley,  California;  Whittier,  California. 

I.  Morphology. 

1.  Vegetative  cells :    Average  dimensions  1.5  x  .4  fx,. 

2.  Endospores :     Form,  elliptical;  size,  1.2  x  .6^^,;  germination,  equatorial; 

rod,  swollen.     Abundantly  produced  on  potato  agar  cultures  3  or 
4  days  old. 

3.  Staining  reactions :     Gram   negative.     Stains   readily  with  the  aniline 

dyes. 

II.  Cultural  Characteristics. 

4.  Agar  strokes,  5  days. 

Beef  agar:     Moderate,  flat,  grayish  white  growth. 

Potato  agar:     Abundant,  moist,  glistening,  grayish  white  growth. 

Peptone  starch  agar:     Moderate,  flat,  grayish  white  growth. 


464  SOIL  SCIENCE 

5.  Potato  cylinder:     Very  scant,   glistening,  colorless  growth  sometimes 

occurs  on  cylinders  held  in  a  moist  chamber  for  30  days,  but  ordi- 
narily no  growth  is  secured. 

6.  Gelatin  stab:     Moderate  growth  at  surface  and  along  track  of  needle 

in  6  days.    After  30  days  napiform  liquefaction  is  observed. 

7.  Beef  broth,  5  days :    Lightly  clouded. 

8.  Litmus  milk:     Reddened  in  5  days;  neither  coagulated  nor  digested  in 

30  days. 

9.  Plate  cultures. 

Ammonia  cellulose  agar,  15  days. 

Form :  Surface  colonies,  round  or  irregularly  round ;  bottom 
colonies  frequently  develop  into  fern-like  growths. 

Size:  Surface  colonies,  2  to  3  mm.;  bottom  colonies  frequently 
attain  a  diameter  of  8  to  10  mm. 

Enzymic  zone:    1  to  3  mm.  in  15  days;  3  to  3.5  mm.  in  25  days. 

Elevation :     Slightly  convex. 

Chromogenesis :  Surface  colonies  show  a  small  white  nucleus ; 
remainder  of  colony,  gray-white;  bottom  colonies  are  fluores- 
cent. 

Internal  structure  :     Coarsely  granular. 

Edge:     Entire  to  undulate. 
Peptone  cellulose  agar,  15  days. 

Form :     Irregularly  round. 

Size :  Surface  colonies  1.5  to  2.5  mm. ;  bottom  colonies  3  to  5  mm, 
Enzymic  zone:  1.5  to  2  mm.  in  15  days;  2.5  to  3  mm.  in  30 
days. 

Elevation :     Convex. 

Chromogenesis :  White  to  grayish  white.  Colonies  sometimes 
show  a  white  nucleus  and  rim. 

Internal  structure:     Coarsely  granular. 

Edge :    Lacerate. 
Peptone  starch  agar,  5  days. 

Form :  Irregular ;  imbedded  colonies  frequently  throw  out  spine- 
like growths. 

Size:    1.5  to  2  mm. 

Enzymic  zone :    1.5  to  2  mm.  in  5  days ;  2.5  to  3.5  mm.  in  10  days. 

Elevation :    Flat. 

Chromogenesis :  White  to  light  grayish  white  in  5  days ;  in  10 
days  the  colonies  become  dark  gray. 

Internal  structure:     Densely  granular. 

Edge :    Lacerate. 
Beef  agar,  5  days. 

Form :  Surface  colonies  round ;  bottom  colonies  spread  out  into 
irregular  growths. 

Size :     Surface  colonies  1.5  to  2  mm. ;  bottom  colonies  10  to  12  mm. 

Consistency :    Very  soft  in  5  days ;  brittle  in  10  days. 

Chromogenesis :  Semi-transparent,  glistening,  gray-white ;  fre- 
quently form  a  small  white  nucleus,  and  many  colonies  are 
more  or  less  concentric  in  structure.  At  an  angle  of  45°  the 
colonies  are  fluorescent. 

Internal  structure :     Granular. 

Edge:     Entire  to  undulate. 


THE  DECOMPOSITION  OF  CELLULOSE  IN  SOILS  465 

Potato  agar,  5  days. 

Form :     Round. 

Size :  2  to  3  mm. ;  bottom  colonies  are  no  larger  than  the  surface 
colonies. 

Elevation:  Decidedly  convex;  in  10  days  colonies  frequently  be- 
come somewhat  unbilicate. 

Consistency :    Butyrous. 

Chromogenesis :  Semi-transparent,  glistening,  light  grayish  white 
to  almost  vitreous.    Many  colonies  exhibit  a  pearl-like  luster. 

Internal  structure:     Finely  granular. 

Edge :     Entire. 

10.  Filter  paper  broths,  15  days.  Paper  is  reduced  to  a  white  pulp-like  mass 

made  up  of  very  short  disintegrated  fibers  which  become  dis- 
tributed through  the  solution  on  slight  agitation.  The  paper  is 
decomposed  very  rapidly  with  ammonium  sulphate,  potassium 
nitrate,  and  peptone  as  the  source  of  nitrogen.  The  decomposi- 
tion takes  place  more  slowly  when  casein  is  added  as  the  source 
of  nitrogen. 
III.    Biochemical  Features. 

11.  Dunham's  solution,  10  days.     No  ammonia  produced ;  nitrite  produced. 

12.  Starch  nitrate  solution,  10  days.    No  ammonia  produced ;  no  nitrite  pro- 

duced. 

13.  Peptone  nitrite  solution,  10  days.     Indol  produced. 

14.  Carbohydrate  broths,  12  days.     No  gas  produced.     Per  cent  of  acidity 

(Fuller's  Scale)    with:    Dextrose,  1.10;  Lactose,  .80;   Saccharose, 
1.00;  Maltose,  1.20;  Glycerine,  .40;  Mannite,  .05;  Starch,  1.20. 

Pseudomonas  arguta,  n.  sp. 
Source:     Soil  from  Azusa,  California;  and  Whittier,  California. 

I.  Morphology. 

1.  Vegetative  cells :     Average  dimensions  .8  x  .3  ft.. 

2.  Endospores :     None  observed. 

3.  Flagella :    1  to  2  in  number ;  6  to  8  /x  in  length. 

4.  Staining  reactions :     Gram   negative.     Stains  readily  with  the  anihne 

dyes. 

II.  Cultural  Characteristics. 

5.  Agar  strokes,  5  days. 

Beef  agar:     Scant,  grayish  white,  filiform  growth. 
Potato  agar:    Moderate,  yellowish,  glistening  white. 
Peptone  starch  agar:     Scant,  white  to  grayish  white. 

6.  Potato  cylinders,  30  days.    No  growth. 

7.  Gelatin  stab:     Moderate  yellowish   growth   at   surface   and  along  the 

track  of  needle  in  10  days ;  no  liquefaction  in  30  days. 

8.  Beef  broth,  5  days  :   Clouded. 

9.  Litmus  milk:     Reddened  in  4  days;  neither  coagulated  nor  digested  in 

30  days. 
10.    Plate  cultures. 

Ammonia  cellulose  agar,  15  days. 
Form :     Round. 

Size :    Surface  colonies,  1  to  2  mm. ;  bottom  colonies,  3  to  4  mm. 
Enzymic  zone:     1  mm.  or  less  in  15  days;  in  30  days  the  zone  fre- 
quently becomes  2  or  3  mm. 


^  SOIL  SCIENCE 

Elevation :     Slightly  convex. 

Chromogenesis :  White  nucleus  and  rim ;  remainder  semi-transpar- 
ent grayish  white. 

Structure :     Grumose. 

Edge :    Entire. 
Peptone  cellulose  agar,  15  days. 

Form :     Round. 

Size :  8  to  12  mm.  in  15  days ;  in  30  days  the  colonies  frequently 
attain  a  diameter  of  20  mm. 

Enzymic  zone :     1  to  2  mm. 

Elevation :     Slightly  convex. 

Chromogenesis :  Central  portion,  usually  from  5  to  7  mm.  in 
diameter,  is  j^ellowish  white.  The  central  portion  of  the 
colony  is  surrounded  by  a  vitreous  zone,  which  in  turn  is  sur- 
rounded by  a  light  grayish  white  rim. 

Internal  structure :     Granular. 

Edge :     Erose. 
Peptone  starch  agar,  5  days. 

Form :     Irregularly  round. 

Size :    5  to  8  mm. 

Enzj'mic  zone :    1  to  2  mm.  in  5  days ;  3  to  4  mm.  in  10  days. 

Elevation :    Flat. 

Consistency  :    Soft  in  5  days ;  older  colonies  become  firm. 

Chromogenesis :  Central  portion,  usually  2  to  3  mm.  in  diameter, 
opaque  white.  The  opaque  portion  of  the  colony  is  surrounded 
by  a  vitreous  zone,  which  in  turn  is  surrounded  by  a  thin  semi- 
transparent  grayish  white  rim. 

Internal  structure :     Granular. 

Edge :    Undulate. 
Beef  agar,  5  days. 

Form :     Round. 

Size :    Surface  colonies,  1  to  1.5  mm. ;  bottom  colonies,  2  to  3  mm. 

Elevation :     Slightly  convex. 

Consistency  :     Soft  to  butyrous. 

Chromogenesis :  Reflected  light,  grayish  white ;  transmitted  light, 
the  colonies  appear  as  semi-transparent  glistening  drops. 

Internal  structure:     Granular. 

Edge :    Entire. 
Potato  agar,  5  days. 

Form :    Round. 

Size:     1  to  2  mm. 

Elevation :    Convex. 

Consistency:    Very  soft. 

Chromogenesis :   Grayish  white,  frequently  develops  brownish  rings. 

Internal  structure :     Granular. 

Edge :    Entire. 
11.     Filter  paper  broths,  15  days.    Paper  is  reduced  to  a  loose  flocculent  mass 

which  disintegrates  very  readily  on  slight  agitation.     Paper  is  de- 
composed  rapidly  when   the  broths   contain   ammonium   sulphate, 

potassium  nitrate,  peptone,  or  casein  as  the  source  of  nitrogen. 


THE  DECOMPOSITION  OF  CELLULOSE  IN  SOILS  467 

III.    Biochemical  Features. 

12.  Dunham's  solution,  10  days.     No  ammonia  formed;  nitrite  formed. 

13.  Starch    nitrate   solution,    10    days.      No    ammonia    formed;    no   nitrite 

formed. 

14.  Peptone  nitrite  solution,  10  days.    No  indol  formed. 

15.  Carbohydrate  broths,  12  days.     No  gas  produced.     Per  cent  of  acidity 

(Fuller's    Scale)    with:     Dextrose,   .30;    Lactose,   .10;    Saccharose, 
.00;  Maltose,  .20;  Glycerine,  .00;  Mannite,  .00;  Starch,  .30. 

Pseudomonas  minuscula,  n.  sp. 

Soukce:     Soil  from  Bonita,  California;  Lordsburg,  California;  and  Sanger,  Cali- 
fornia. 
I.    Morphology. 

1.  Vegetative  cells :    Average  dimensions,  .9  x  .5  fx. 

2.  Endospores :    None  observed. 

3.  Flagella :     1,  rarely  2  in  number ;  3  to  4  yu,  in  length. 

4.  Staining   reactions :     Gram   positive.      Stains   readily   with   the  aniline 

dyes. 
n.    Cultural  Characteristics. 

5.  Agar  strokes,  5  days. 

Beef  agar:     Moderate,  flat,  grayish  white,  filiform  growth. 

Potato  agar:     Abundant,  moist,  glistening,  grayish  to  yellowish  white. 

Peptone  starch  agar:     Moderate,  grayish  white,  filiform  growth. 

6.  Potato   cylinders:     No  apparent  growth  after  30  days,   but  potato  is 

bleached  along  the  track  of  the  inoculating  needle. 

7.  Gelatin  stab:     Moderate  growth  at  surface  and  alone  track  of  needle 

in  6  days ;  slight  napiform  liquefaction  after  30  days. 

8.  Beef  broth,  5  days  :     Turbid. 

9.  Litmus  milk:     Reddened  in  6  days;  neither  coagulated  nor  digested  in 

30  days. 
10.     Plate  cultures. 

Ammonia  cellulose  agar,  15  days. 

Form  :     Round  or  irregularly  round. 

Size :     Surface  colonies  1  to  2  mm. ;  bottom  colonies  may  attain  a 

diameter  of  6  to  10  mm. 
Enzymic  zone :     1.5  to  2  mm. 
Elevation :     Slightly  depressed. 
Consistency :     Soft. 
Chromogenesis :     Nucleus  and  rim  are  white,  remainder  of  colony 

grayish  white. 
Internal  structure:     Granular. 
Edge :     Undulate. 
Peptone  cellulose  agar,  15  days. 

Form :    Round  or  irregularly  round. 

Size:    1  to  2  mm. ;  bottom  colonies  frequently  attain  a  diameter  of 

10  mm. 
Enzymic  zone:     1  to  1.50  mm. 
Elevation:     SHghtly  convex. 
Consistency :     Soft. 

Chromogenesis :     White  to  grayish  white. 
Internal  structure:     Granular. 
Ejdge :    Erose. 


468  ^OIL  SCIENCE 

Peptone  starch  agar,  5  days. 

Form :     Irregular,  round. 

Size:    1  to  1.5  mm. 

Enzymic  zone :    2  to  3  mm. 

Elevation:     Slightly  convex. 

Consistency :     Firm. 

Chromogenesis :     White  to  light  grayish  white. 

Internal  structure :     Granular. 

Edge :    Lacerate. 
Beef  agar,  5  days. 

Form :     Round. 

Size:     1  mm.  or  less. 

Elevation:     Slightly  convex. 

Consistency :     Butyrous ;  old  colonies  become  brittle. 

Chromogenesis :  By  reflected  light  colonies  are  gray  white ;  by 
transmitted  light  they  appear  as  light,  semi-transparent  smoky 
drops. 

Internal  structure :     Finely  granular. 

Edge :    Entire. 
Potato  agar,  5  days. 

Form :    Round. 

Size:    1  to  2  mm. 

Elevation :    Convex. 

Consistency :     Soft. 

Chromogenesis :  Gray-white,  sometimes  showing  concentric  struc- 
ture. 

Internal  structure :     Granular. 

Edge :    Entire. 

11.  Filter  paper  broths,  15  days.    Paper  reduced  to  a  felt-like  grayish  white 

mass  which  breaks  up  into  small  particles  on  very  slight  agitation. 
Paper  destroyed  more  rapidly  in  solutions  containing  ammonium 
sulphate,  peptone,  or  potassium  nitrate  than  in  solutions  containing 
casein. 
III.    Biochemical  Features. 

12.  Dunham's  solution,  10  days.     No  ammonia  produced;  nitrite  produced. 

13.  Starch  nitrate  broth,  10  days.    No  ammonia  produced ;  nitrite  produced. 

14.  Peptone  nitrite  solution,  10  days.     Indol  produced. 

15.  Carbohydrate  broths.     No  gas  produced.     Per  cent  of  acidity  (Fuller's 

Scale)    with:     Dextrose,    1.20;    Lactose,    1.10;    Saccharose,    1.00; 
Maltose,  1.10;  Glycerine,  .00;  Mannite,  .00;  Starch,  .90. 

Pseudomonas  mira,  n.  sp. 

Source:    Soil  from  Corona,  California;  Glendora,  California;  Monrovia,  California. 

I.  Morphology. 

1.  Vegetative  cells:     Average  dimensions,  1.6  x  .4  fx- 

2.  Endospores :    None  observed. 

3.  Flagella :     1  in  number ;  4  to  6  yu.  in  length. 

4.  Staining  reactions :     Gram  negative.     Stains  readily  with  the  atiiline 

dyes. 

II.  Cultural  Characteristics. 

5.  Agar  strokes,  5  days. 

Beef  agar:     Moderate,  flat,  grayish  white,  somewhat  iridescent 


THE  DECOMPOSITION  OF  CELLULOSE  IN  SOILS    '         469 

Potato  agar:     Abundant,  grayish  white;  becomes  grayish  brown  in  10 

days. 
Peptone  starch  agar:     Abundant,  moist,  grayish  white;  in  10  days  the 
growth  at  the  bottom  of  the  slope  becomes  flesh  colored. 

6.  Potato  cylinder:     Moderate,  grayish  white,  leathery  growth  in  15  days. 

7.  Gelatin  stab:     Good  growth  at  surface  and  along  track  of  needle  in  6 

days;  no  liquefaction  in  30  days. 

8.  Beef  broth,  5  days :     Heavily  clouded. 

9.  Litmus  milk:     Blued  in  10  days;  neither  coagulated  nor  digested  in  30 

days. 
10.    Plate  cultures. 

Ammonia  cellulose  agar,  15  days. 

Form  :     Round  or  irregularly  round. 

Size:     1  to  1.5  mm. 

Enzymic  zone:     1  to  2  mm.  in  15  days;  3  to  4  mm.  in  30  days. 

Elevation:     Slightly  convex. 

Chromogenesis :     Surface  colonies  opaque  white ;  bottom  colonies 
semi-transparent  grayish  white. 

Internal  structure:     Granular. 

Edge :     Erose. 
Peptone  cellulose  agar,  15  days. 

Form :     Round  to  irregularly  round. 

Size :     Surface  colonies,  1  to  2  mm. ;  bottom  colonies  6  to  8  mm. 

Enzymic  zone:     1  mm.  or  less  in  15  days;  2  to  3  mm.  in  30  days. 

Elevation :    Slightly  convex. 

Chromogenesis:      Surface   colonies   have   a   small   white   nucleus, 
remainder  of  colonies  grayish  white. 

Internal  structure:     Granular. 

Edge  :     Entire  to  undulate. 
Peptone  starch  agar,  5  days. 

Form :    Irregularly  round. 

Size:    2  to  3  mm. 

Enzymic  zone:    1.5  to  2  mm. 

Elevation :     Slightly  convex. 

Consistency :    Firm. 

Chromogenesis:   White  to  light  grayish  white;   sometimes  shows 
a  small  white  nucleus. 

Internal  structure:     Granular. 

Edge :     Lacerate. 
Beef  agar,  5  days. 

Form:     Surface  colonies  are  round;  bottom  colonies  spread  pro- 
fusely. 

Size :     2  to  3  mm. 

Elevation :    Convex. 

Consistency:     Soft  to  butyrous. 

Chromogenesis :     Small  white  nucleus,  remainder  gray-white. 

Internal  structure:     Granular. 

Edge :    Lacerate. 
Potato  agar,  5  days. 

Form :     Round. 

Size :    2  to  5  mm. 

Elevation :    Convex. 
(33) 


470  SOIL  SCIENCE 

Consistency :     Very  soft. 

Chromogenesis :     Glistening,  grayish  white;  surface  colonies  have 

a  pearl-like  luster. 
Internal  structure :     Granular. 
Edge :    Lacerate. 

11.  Filter  paper  broths,   15  days.     Paper  attacked  along  the  edge  nearest 

surface  of  solution;  in  20  days  the  paper  is  very  completely  dis- 
integrated.   The  paper  decomposed  at  about  the  same  rate  in  solu- 
tions  containing  ammonium   sulphate,   potassium   nitrate,  peptone, 
or  casein  as  the  source  of  nitrogen. 
III.    Biochemical  Features. 

12.  Dunham's  solution,  10  days.     Ammonia  produced;  no  nitrite  produced. 

13.  Starch  nitrate  solution.     Ammonia  produced ;  nitrite  produced. 

14.  Peptone  nitrite  broth,  10  days.    No  indol  produced. 

15.  Carbohydrate  broths,  12  days.     No  gas  produced.     Per  cent  of  acidity 

(Fuller's   Scale)    with:    Dextrose,  1.25;  Lactose,   .50;   Saccharose, 
1.10;  Maltose,  1.20;  Glycerine,  .30;  Mannite,  .25;  Starch,  1.50. 

Summary  of   Specific  Characteristics  of   Cellulose-Dissolving 

Bacteria 
The  detailed  description  of  the  cellulose-dissolving  bacteria  known 
today  are  scattered  through  several  publications.  In  the  identification  of 
newly  isolated  forms  or  in  comparing  the  specific  characteristics  of  de- 
scribed forms,  it  is  obviously  desirable  that  the  more  important  morpholo- 
gical and  cultural  features  of  the  cellulose-dissolving  organisms  known  at 
this  time  be  brought  together  in  such  a  way  as  to  afford  a  ready  compari- 
son. The  more  important  morphological  and  cultural  features  of  the 
cellulose-dissolving  bacteria  are  briefly  summarized  in  Table  II.  The  bio- 
chemical reactions  of  the  different  species  are  summarized  in  Table  III. 

Provisional  Key  for  Identifying  and  Comparing  Species  of  Bac- 
teria WHICH  Dissolve  Cellulose 
In  order  to  facilitate  further  the  identification  and  classification  of 
cellulose-dissolving  bacteria  a  diagrammatic  key  has  been  prepared.  In 
the  preparation  of  a  key  of  this  character,  it  is  desirable  to  use  single 
diagnostic  features  by  means  of  which  the  organisms  may  be  separated 
into  smaller  and  smaller  groups  until  all  species  are  finally  separated  from 
each  other.  In  such  an  arrangement,  it  is  obvious  that  the  features  used 
must  have  a  high  degree  of  constancy.  In  the  preparation  of  the  follow- 
ing key,  only  those  features  which  have  remained  constant  through  a 
number  of  cultures  have  been  used  and  it  is  believed  that  when  the  key  is 
used  in  conjunction  with  the  data  presented  in  Tables  II  and  III,  it  will 
be  found  of  much  help  in  separating  a  particular  organism  from  its  con- 
geners or  in  assigning  it  a  provisional  place  in  a  system  of  classification. 

Importance  of  Cellulose  Destruction  in  Soils. 
All  organisms  make  up  for  the  waste  incurred  in  their  vital  activities 
by  the  consumption  of  chemical  energy.    This  necessary  energy  is  for  the 


THE  DECOMPOSITION  OF  CELLULOSE  IN  SOILS 


471 


TABLE  II 

COMPARATIVE    SUMMARY   OF   THE   MORE    IMPORTANT    MORPHOLOGICAL    AND 

CULTURAL  FEATURES  OF  CELLULOSE-DISSOLVING  BACTERIA 


Morphology 

Cultural  features 

is 

B  S 
iS.S 

o 

o 
o. 
in 

o 

C  O 

Beef 

agar 

•a 
o  9 

u  O 
Mo 

•a 

SI 

3 
^  2 

Litmus  milk 

o 
1-. 

O   «J 

^  to 
V  o 

>  s 

^"2 

V  u 

rtT3 

B.  albidus 

l.Ox.4 

1-3 

— 





— 

— 

— 

— 

+ 

— 

— 

B.  almus 

1.2  X. 5 

1-5 

— 





+ 

+ 

— 

— 

+ 

— 

— 

B.  amylolyticus 

(28) 

3.5  X. 7 

10-16 

+ 

— 

+ 

— 

+ 

+ 

— 

+ 

— 

— 

B.   aurogenus 

(29) 

1.4  X  .4 

1-3 

— 

— 

+ 

+ 

+ 

+ 

+ 

+ 

— 

+ 

B.  bibulus 

(42) 

1.3  X. 4 

1-4 

— 

— 

+ 

— 

+ 

+ 

+ 

+ 

— 

— 

B.  biazoteus 

(29) 

.8x.5 

1-3 

— 

— 

+ 

+ 

+ 

+ 

+ 

+ 

— 

— 

B.  caesius 

(29) 

1.5  X. 4 

1-2 

— 

— 

— 

— 

+ 

+ 

— 

+ 

— 

+ 

B.  cellaseus 

(29) 

1.2  X. 5 

1-3 

— 



— 

— 

— 

+ 

— 

+ 

— 

— 

B.  concitatus 

1.2  x. 5 

1-3 

— 

— 

+ 

+ 

+ 

+ 

— 

+ 

— 

— 

B.  cytaseus 

2.7  X. 5 

10-18 

+ 

+ 

— 

— 

— 

— 

— 

— 

— 

— 

B.  desidiosus 

1.0  X. 4 

1-3 

— 

— 

— 

— 

+ 

— 

— 

+ 

— 

— 

B.  festinus 

2.0  X. 6 

1-3 

+ 

— 

— 

— 

— 

— 

— 

+ 

— 

+ 

B.  galbus 

(29) 

l.Ox.4 

1-3 

— 

— 

+ 

+ 

+ 

+ 

— 

+ 

— 

— 

B.  gelidus 

(29) 

1.2  X. 4 

1-3 

— 



+ 

— 

+ 

— 

+ 

+ 

— 

+ 

B.  gilvus 

1.5  x  .5 

1-4 

— 

— 

— 

+ 

+ 

— 

+ 

+ 

— 

— 

B.  imminutus 

1.5  x. 2 

1-5 

+ 

+ 

— 

— 

— 

— 

— 

— 

— 

— 

B.  iugis 

1.4  X  .4 

1-3 

— 

— 

— 

— 

+ 

+ 

+ 

+ 

— 

— 

B.  pusilus 

(29) 

1.1  x. 6 

1-3 

— 

— 

— 

— 

+ 

— 

— 

+ 

— 

— 

B.   rossicus 

(28) 

1.2  X. 3 

1-5 

— 

+ 

+ 

— 

+ 

+ 

+ 

— 

+ 

— 

B.   subalbus 

.8x.4 

1-3 

— 



+ 

— 

+ 

— 

— 

+ 

— 

— 

Eact.  acidulum 

(29) 

1.0  X. 3 

— 

— 

— 

— 

— 

— 

— 

— 

+ 

— 

— 

Bact.  castigatum 

1.2  X  .4 

— 

— 

— 

+ 

— 

+ 

— 

— 

+ 

— 

— 

Bact.  fimi 

(42) 

.9x.4 

— 

— 



+ 

— 

+ 

+ 

•f 

+ 

— 

— 

Bact.  flavigenum 

(28) 

l.Ox.4 

— 

— 

— 

+ 

+ 

+ 

+ 

+ 

+ 

— 

— 

Bact.  idoneum 

1.5X.5 

— 

— 

— 

— 

+ 

+ 

+ 

+ 

+ 

— 

— 

Bact.  liquatum 

(42) 

1.7X.4 

— 

— 

— 

+ 

+ 

+ 

+ 

-(- 

+ 

— 

— 

Bact.  lucrosum 

1.3  X. 4 

— 

— 

— 

+ 

— 

+ 

— 

— 

— 

— 

— 

Bact.  paludosum 

1.5  X. 4 

— 

+ 



-f 

— 

+ 

-f 

+ 

+ 

— 

— 

Bact.  udum 

(29) 

l.Sx.5 

— 

— 

— 

+ 

— 

+ 

O- 

+ 

+ 

— 

— 

Ps.  arguta 

.8x.3 

1-2 

— 

— 

— 

— 

+ 

— 

— 

+ 

— 

— 

Ps.  effusa 

(29) 

1.7  X. 4 

1-6 

— 

— 

+ 

+ 

+ 

+ 

+ 

— 

+ 

+ 

Ps.   minuscula 

.9x.5 

1-2 

— 

— 

+ 

— 

4- 

-f 

— 

+ 

— 

— 

Ps.  mira 

1.6X.4 

1 

— 



+ 

— 

+ 

— 

-f 

— 

+ 

— 

Ps.  perlurida 

(29) 

l.Ox.4 

1-3 

— 

— 

+ 

— 

+ 

+ 

+ 

+ 

— 

-f 

Ps.  subcreta 

(42) 

1.4X.4 

1-5 

— 

— 

— 

— 

— 

— 

— 

— 

— 

— 

Ps.  tralucida 

(29) 

1.2  X. 6 

1-2 

— 

— 

— 

— 

+ 

— 

— 

+ 

— 

— 

most  part  derived  from  the  oxidation  of  carbon.  Green  plants  through 
the  agency  of  their  chlorophyll  have  the  power  of  utilizing  the  radiant 
energy  of  the  sunlight  to  decompose  the  carbon  dioxide  of  the  air  and  use 
it  in  their  metabolic  processes.  These  plants  receive  thereby  not  only  the 
necessary  energy  for  their  own  life,  but  store  up  an  enormous  quantity 
of  potential  energy  upon  which  animals  and  those  plants  which  do  not  con- 
tain chlorophyll  are  largely  dependent.    Moreover,  the  successful  growth 


472 


SOIL  SCIENCE 


TABLE  III 

COMPARATIVE   SUMMARY   OF  THE  BIOCHEMICAL   FEATURES   OF 

CELLULOSE-DISSOLVING  BACTERIA 


Dunham's 

Nitrate 

Per  cent  acid  produced  in   12  days 

solution 

solution 

o 

-a 
c 
1-1 

at  30°  C. 

a 
"S 

1 
E 
< 

V 

a 

'c 
o 
B 

B 
< 

o 

V 

Q 

V 

o 
o 

o 
a 

1 

(U 

o 

1) 
o 

V 

'S 

c 

J3 
o 

Ui 

a 

B.  albidus 

— 

— 

— 

— 

— 

0.50 

0.20 

0.10 

0.10 

0.10 

0.10 

0.10 

B.  almus 

— 

— 

— 

— 

— 

1.30 

0.80 

1.00 

1.20 

0.40 

0.00 

0.60 

B.  amylolyticus 

(28) 

— 

— 

— 

— 

— 

0.90  i  0.90 

0.90 

0.80 

0.90 

0.90 

1.40 

B.  aurogenus 

(29) 

+ 

+ 

+ 

+ 

— 

1.80 

1.40 

1.40 

1.20 

0.70 

0.00 

1.60 

B.  bibulous 

(42) 

+ 

+ 

— 

— 

+ 

1.80 

1.30 

1.50 

1.50 

0.40 

1.20 

2.00 

B.  biazoteus 

(29) 

— 

+ 

— 

+ 

— 

2.00 

1.10 

1.00 

0.90 

0.50 

0.00 

1.50 

B.  caesius 

(29) 

+ 

+ 

+ 

+ 

— 

1.90 

1.50 

1.40 

1.10 

0.50 

0.20 

1.40 

B.  cellaseus 

(29) 

— 

+ 

— 

— 

— 

1.40 

0.40 

1.40 

0.80 

0.30 

1.10 

1.20 

B.  concitatus 

— 

— 

— 

+ 

+ 

1.80 

0.85 

1.30 

1.30 

0.45 

0.00 

1.35 

B.  cytaseus 

— 

— 

— 

— 

— 

0.00 

0.00 

0.00 

0.00 

0.00 

0.00 

0.00 

B.  desidiosus 

— 

+ 

— 

+ 

+ 

0.80 

0.10 

0.00 

0.60 

0.00 

0.00 

0.20 

B.  festinus 

— 

— 

— 

+ 

+ 

0.50 

0.40 

0.00 

0.65 

0.05    0.00 

0.60 

B.  galbus 

(29) 

+ 

+ 

— 

— 

+ 

1.40 

1.30 

1.20 

1.30 

1.20 

0.00 

1.30 

B.  gelidus 

+ 

+ 

— 

— 

— 

1.20 

1.20 

0.80 

1.20 

0.40 

0.00 

1.40 

B.  gilvus 

+ 

+ 

— 

+ 

+ 

1.20 

0.75 

0.80 

1.00 

0.40 

0.00 

1.00 

B.  imminutus 

— 

— 

_ 

— 

— 

0.00 

0.00 

0.00 

0.00 

0.00 

0.00 

0.00 

B.  iugis 

+ 

+ 

— 

+ 

— 

0.80 

1.10 

1.60 

1.55 

0.45 

0.20 

1.50 

B.  pusilus 

(29) 

+ 

+ 

— 

+ 

— 

1.50 

1.40 

1.60 

1.40 

0.50 

0.00 

1.50 

B.  rossicus 

(28) 

+ 

— 

— 

+ 

— 

^1.0 

-1.4 

-1.4 

-1.6 

-1.4 

-1.5 

-1.2 

B.  subalbus 

+ 

+ 

— 

+ 

— 

1.60 

1.00 

1.40 

1.20 

0.70 

0.20 

1.40 

Bact.  acidulum 

(29) 

— 

— 

— 

— 

— 

0.40 

0.30 

0.30 

0.50 

0.00 

0.00 

0.00 

Bact.  castigatum 

— 

+ 

— 

— 

— 

1.50 

1.10 

1.00 

1.45 

0.55 

0.00 

1.40 

Bact.  fimi 

(42) 

+ 

+ 

— 

+ 

+ 

1.60 

0.90 

1.60 

1.40 

0.80 

0.00 

1.60 

Bact.  flavigenum 

(28) 

— 

+ 

— 

+ 

— 

1.00 

0.90 

0.70 

0.90 

0.30 

0.10 

1.40 

Bact.  idoneum 

— 

+ 

— 

+ 

— 

1.60 

1.20 

1.20 

1.40 

0.70 

0.00 

1.40 

Bact.  liquatum 

(42) 

+ 

— 

— 

+ 

+ 

1.30 

1.00 

1.30 

1.20 

0.20 

0.00 

1.40 

Bact.  lucrosum 

— 

+ 

— 

— 

— 

0.20 

0.10 

0.00 

0.15 

0.00 

0.05 

0.15 

Bact  paludosum 

— 

+ 

— 

— 

+ 

1.10 

0.80 

1.00 

1.20 

0.40 

0.05 

1.20 

Bact  udum 

(29) 

— 

+ 

+ 

+ 

— 

1.40 

1.30 

1.40 

1.20 

0.00 

0.00 

1.40 

Ps.  arguta 

— 

+ 

— 

— 

— 

0.30 

0.10 

0.00 

0.20 

0.00 

0.00 

0.30 

Ps.  effusa 

(29) 

+ 

— 

— 

+ 

— 

2.10 

-.50 

-.70 

0.60 

0.30 

0.20 

1.20 

Ps.  minuscula 

— 

+ 

— 

+ 

+ 

1.20 

1.10 

1.00 

1.10 

0.00 

0.00 

0.90 

Ps.  mira 

+ 

— 

— 

+ 

_ 

1.25 

0.50 

1.10 

1.20 

0.30 

0.25 

l.SO 

Ps.  Perlurida 

(29) 

+ 

— 

— 

— 

— 

1.80 

1.50 

1.50 

1.20 

0.60 

1.50 

2.00 

Ps.  subcreta 

(42) 

— 

— 

— 

— 

— 

0.60 

0.50 

0.10 

0.50 

0.00 

0.00 

0.60 

Ps.  tralucida 

(29) 

— 

+ 

— 

+ 

— 

1.30 

0.70 

1.60 

1.00 

0.40 

0.20 

1.60 

of  future  generations  of  green  plants  is  largely  controlled  by  the  liberation 
of  this  large  store  of  potential  energy  through  decomposition  processes  in 
the  soil. 

It  is  well  known  that  through  the  agency  of  microorganisms,  vegeta- 
ble matter  is  gradually  transformed  into  the  complex  mixtures  ordinarily 
known  as  humus.  In  all  cultivated  soils,  it  is  important  to  replenish 
from  time  to  time  the  organic  matter  in  the  soil  by  the  application  of 
stable  manure,  green  manure,  etc.     In  semi-arid  soils  where  the  growth 


THE  DECOMPOSITION  OF  CELLULOSE  IN  SOILS 


473 


w 

H 

u 

< 
m 

o  « 

w   t! 

W     « 

M  Oh 
U  , 
W    to 


•'=i 


o         "J 


«        2 
u  —  c   -< 

3  O       ) 


i 


-5i 

O 


s— .« 


-  <^ 

o 


«3 

m 
^ 

cr 

hJ 

oa 

'^  -^ 


U   CQ 


o  X 

u     ^ 

o     . 


-tA 


Si  CQ 


U  CQ 


boX 


.^   CQ 


o 


^Z.  03 


474 


SOIL  SCIENCE 


Pi 

w 

H 

U 

< 

pa 

xs 

fe 

o 

o  a 

1-r 

P3 

t«  t: 

u 

w   « 

•s 

*-;  Ph 

TO 

o 

'«^ 

W    co 

s 

f^    ^ 

^  ::j 

_c 

O    '~1 
2  t3 

V 

§5 

'u 

^1   m 

o 

^   D 

O   Z 

u  w 

o 

Q^ 

g 

fe 

< 

o 

g 

>3 

dH 

H 

Cxj 

0 

l-l 

p< 

o 

fe 

>- 

w 

w 

^ 

^ 

o 

l-( 

tn 

t-( 

> 

O 

P4 

fx< 

ii  — -="  ■< 


3— S    J 


p:°5 


_>  ~ 


^   5 


J  ■•? 


^;  cq 


—  o   < 


o  I 


hJ   03 


2_°  J 
O       Jr.  1 


hJ  K3 


tf3  03 


<.'Z  OQ 


THE  DECOMPOSITION  OF  CELLULOSE  IN  SOILS 


475 


U 
H 
U 

< 

o 

cu  m 

?^^ 

S  w 
o  o 
u 

o 

< 

o 

I— I 
>^ 

g 

o 


.2  — o  ■< 
5   E  > 


^  ci 


O  Ji 


3  ^. 


ba  J 
2  1 


ri'  5 


i  -u    < 


O  13 


60  -^ 
2  on 


-;^ 


■1-.  ^ 


•J  cq 


V,^.  CQ 


o  a 


476 


SOIL  SCIENCE 


O    H^ 

<  a. 


w 

H 

u 

< 
m 

t/3  ^ 

^2 

o '--' 

o  w 
u  o 

p 
z 

<; 

o 

2 

>^ 
b 

H 

w 

Q 

Pi 
O 

>H 

< 

Z 

o 


a 

o 

fa     .L 

w  c4    -< 


K  a. 


E 
o 

fa 

Z 


•;3a^ 


o 


Ph  a. 


rt  s 


^1 
<  S 

Z  a. 


Z  a. 


THE  DECOMPOSITION  OF  CELLULOSE  IN  SOILS  477 

of  native  vegetation  has  been  limited  by  the  meager  rainfall,  the  humus 
content  of  the  virgin  soil  may  be  as  low  as  0.30  per  cent  or  even  less. 
When  such  soils  are  brought  under  intensive  cultivation  by  means  of  irri- 
gation, the  scarcity  of  humus  soon  manifests  itself  by  the  development  of 
injurious  changes  in  the  tilling  qualities  of  the  land.  Many  such  lands 
soon  fail  to  give  satisfactory  crops  or  respond  to  the  application  of  com- 
mercial fertilizers  unless  the  supply  of  organic  matter  is  maintained  by 
liberal  applications  of  barnyard  manure,  green  manures,  etc. 

As  the  larger  part  of  carbonaceous  matter  added  to  soils  in  plant  re- 
sidues, stable  manure,  etc.  is  cellulose, — the  gradual  decomposition  of 
the  cellulose  in  soils  in  association  w^ith  the  nitrogenous  compounds  must 
play  a  very  prominent  role  not  only  in  maintaining  the  humus  content  of 
soils,  but  in  securing  the  proper  development  of  the  many  important  bio- 
logical processes.  The  humus  content  of  the  soil  is  considered  by  many  to 
serve  as  the  depository  of  the  insoluble  nitrogen  of  the  soil  w^hich  consti- 
tutes the  reserve  supply  for  crops.  It  is  probable  but  not  certain 
that  this  insoluble  nitrogen  through  the  process  of  nitrification  fur- 
nishes the  main  nitrogen  supply  to  plants.  The  fixation  of  atmos- 
pheric nitrogen  in  the  soil  is  dependent  upon  the  development  of  micro- 
organisms which  requires  large  quantities  of  organic  carbon  as  food.  Dur- 
ing recent  years,  investigations  by  Koch  (34),  Pringsheim  (63),  and 
McBeth  (42)  have  shown  that  cellulose  may  serve  as  a  valuable  source 
of  energy  for  these  organisms.  However,  cellulose  is  an  extremely  in- 
ert compound  and  the  carbon  contained  therein  can  be  utilized  by  the 
nitrogen  fixing  bacteria  only  after  the  cellulose  has  been  converted  into 
less  refractory  compounds  by  the  cellulose-dissolving  bacteria.  It  is  ob- 
vious, therefore,  that  the  work  performed  by  these  organisms  is  of  fimda- 
mental  importance  in  releasing  the  great  store  of  energy  locked  up  in 
cellulose.  In  view  of  the  fact  that  the  cellulose  added  to  the  soil  repre- 
sents a  large  amount  of  potential  energy,  the  value  of  which  depends 
upon  the  nature  of  the  compounds  formed  in  its  decomposition,  it  be- 
comes quite  important  to  inquire  into  the  nature  of  the  compounds  pro- 
duced by  the  celFulose-dissolving  bacteria.  Earlier  investigations  by 
Popoff  (61),  Toppeiner  (78),  Hoppe-Seyler  (25),  Gayon  (15),  Deherain 
(13),  Schloesing  (74),  Van  Senus  (76),  Omeliansky  (50),  and  others 
seemed  to  indicate  that  cellulose  undergoes  a  direct  gaseous  fermentation 
in  which  a  very  large  percentage  of  the  carbon  is  converted  into  carbon 
dioxide  and  methane.  Hoppe-Seyler  was  of  the  opinion  that  cellulose 
was  dissolved  according  to  the  following  formula: 

(1)  The  hydration  of  the  cellulose  with  the  formation  of  a  hexose, 

CeHjoO,  -f  H^O  =  CeHj.Oe ;  and 

(2)  The  destruction  of  the  carbohydrate  with  the  formation  of  equal 
quantities  of  carbon  dioxide  and  methane, 

C^H,,0,  =  3CO,  -f  3CH,. 


478  SOIL  SCIENCE 

If  cellulose  undergoes  a  direct  gaseous  fermentation  in  which  a  large 
part  or  all  of  the  carbon  is  returned  to  the  air  in  the  first  decomposition 
processes,  the  addition  of  cellulose  to  the  soil  would  undoubtedly  be  of 
far  less  value  than  if  the  decomposition  products  formed  by  the  cellulose- 
dissolving  bacteria  were  non-volatile  and  remain  in  the  soil,  where  they 
may  assist  in  maintaining  the  humus  content  or  may  serve  as  a  source  of 
energy  for  important  groups  of  bacteria,  such  as  the  nitrogen  fixing  or- 
ganisms. 

It  is  well  known  that  fermentation  processes  in  the  soil  resulting  in  a 
decomposition  of  the  organic  matter  may  give  rise  to  large  quantities  of 
CO2  and  CH4.  However,  we  have  been  unable  to  show  that  these  com- 
pounds are  due  to  the  activity  of  cellulose-dissolving  bacteria.  None  of 
the  cellulose-dissolving  forms  studied  in  our  investigations  give  rise  to 
gaseous  products  in  cellulose  or  sugar  solutions  in  which  they  make  a 
luxuriant  growth.  Under  natural  conditions  the  compounds  formed  by 
the  cellulose-dissolving  bacteria  will  of  course  be  seized  upon  by  a  host 
of  other  microorganisms  and  split  up  into  simple  compounds.  In  some 
soils  the  destruction  may  be  extremely  rapid  and  complete,  resulting  in 
the  formation  of  little  humus ;  under  such  conditions  a  very  large  per- 
centage of  the  carbon  in  the  cellulose  is  quickly  liberated  as  CO^.  How- 
ever, the  COo  formed  is  presumably  due  in  all  cases  to  secondary  fermen- 
tations by  the  action  of  the  organisms  upon  the  products  produced  by  the 
cellulose-dissolving  organism.  Likewise,  the  organic  acids  noted  by 
early  investigators  were,  for  the  most  part  at  least,  presumably  due  to 
secondary  fermentation  and  not  to  the  action  of  the  cellulose-dissolving 
forms. 

The  influence  of  the  products  of  bacterial  activity  in  rendering  soluble 
various  essential  mineral  constituents  of  the  soil  has  come  to  be  recog- 
nized as  of  considerable  importance  in  maintaining  the  fertility  of  soils. 
It  would  seem  that  the  insoluble  compounds  of  potassium,  phosphorus, 
magnesium,  calcium,  iron,  sulphur,  and  even  silicon  may  be  rendered 
soluble  through  the  production  of  carbon  dioxide  and  organic  acids 
which  result  from  the  decomposition  of  cellulose  and  other  organic  mat- 
ter in  soils.  It  is  well  known  that  limestones  are  quickly  dissolved  by 
carbonated  waters,  even  granite  and  rocks  related  to  it  are  attacked  be- 
cause of  the  feldspar  minerals  which  contain  potash,  sodium  and  calcium 
together  with  aluminum.  The  results  of  this  action  would  seem  to  be 
highly  important  in  many  western  soils  as  the  liberation  of  the  aluminum 
results  in  the  formation  of  clay  which  has  an  important  influence  on  the 
physical  condition  of  the  soil,  while  the  potassium  is  one  of  the  essential 
nutrients  of  plant  growth. 


THE  DECOMPOSITION  OF  CELLULOSE  IN  SOILS  479 

Phosphoric  acid  is  so  tenaciously  held  by  most  soils  that  ordinary 
leaching  of  the  soil  due  to  natural  rainfall  or  irrigation  would  seem  to 
bring  very  small  amounts  of  this  valuable  substance  into  solution.  The 
action  of  carbon  dioxide  upon  the  insoluble  phosphorus  compounds  of  the 
soil  may  proceed  as  foUovv^s : 

Ca,(POJ,  +  2CO2  +  2H3O  =  Ca^H^CPOJ^  +  Ca(HC03)p 

A  large  portion  of  the  CO,  resulting  from  the  decomposition  of 
cellulose  or  other  carbonaceous  materials  in  soils  is  ultimately  returned 
to  the  atmosphere  where  it  may  be  used  over  and  over  again  in  the  manu- 
facture of  sugar,  starches,  cellulose,  etc.  in  new  generations  of  plants.  If 
it  were  not  for  the  activity  of  cellulose-dissolving  organisms  in  the  soil 
developing  in  association  with  gas  producing  organisms,  the  cycle  of 
change  to  which  carbon  is  subject  would  soon  come  to  a  standstill  and  the 
carbon  supply  of  plants  soon  be  depleted. 

The  importance  of  cellulose  destruction  in  soil  may  then  be  summar- 
ized as  follows : 

1.  The  decomposition  of  cellulose  under  proper  soil  conditions  and 
in  association  with  the  nitrogenous  compounds  of  plant  tissues  makes 
possible  the  maintenance  of  the  soil  humus  which  is  so  essential  in  main- 
taining the  proper  tilling  qualities  of  the  land. 

2.  The  cellulose  added  to  the  soil  represents  a  large  amount  of  poten- 
tial energy  which  must  have  a  marked  stimulating  effect  on  nitrogen 
fixation  and  many  other  important  biological  processes  going  on  in  the 
soil. 

3.  The  decomposition  of  cellulose  in  soils,  under  proper  conditions, 
results  in  the  formation  of  large  quantities  of  carbon  dioxide.  The  action 
of  carbonic  acid  in  rendering  available  various  mineral  constituents  of  the 
soil  is  recognized  as  an  important  factor  in  the  maintenance  of  soil  fer- 
tility. 

4.  Through  the  decomposition  processes,  the  carbon  locked  up  in  the 
cellulose  is  ultimately  returned  to  the  atmosphere,  thus  maintaining  the 
carbon  cycle  and  rendering  the  carbon  supply  for  plants  inexhaustible. 

Summary 

1.  The  cellulose  agar  plate  method  is  the  most  satisfactory  for  iso- 
lating pure  strains  of  bacteria,  filamentous  fungi  or  Actinomyces  which 
have  the  power  of  dissolving  cellulose. 

2.  In  the  preparation  of  precipitated  cellulose  for  cellulose  agar,  the 
copper-ammonium-cellulose  solution  as  well  as  the  acid  used  should  be 
very  dilute.  If  either  of  the  solutions  are  too  concentrated,  the  precipi- 
tate is  likely  to  be  coarse,  which  not  only  makes  it  difficult  to  wash,  but 
unsatisfactory  for  the  preparation  of  culture  media.  A  uniformly  fine 
cellulose  precipitate  can  be  secured  by  diluting  one  part  of  the  copper- 
ammonium-cellulose  solution  with  forty  parts  of  water  and  mixing  with 


480  SOIL  SCIENCE 

a  dilute  hydrochloric  acid  solution,  prepared  by  adding  one  part  of  con- 
centrated acid  to  twenty  parts  of  water. 

3.  Cellulose  agar  can  be  prepared  from  the  cellulose  in  plant  tissues 
by  grinding  the  dry  plant  substances  to  a  flour  and  isolating  the  cellu- 
lose in  a  pure  state  from  the  finely  ground  substance.  Cellulose  prepared 
in  this  way  is  quite  as  satisfactory  for  the  preparation  of  cellulose  agar  as 
that  prepared  from  filter  paper  in  the  ordinary  way. 

4.  Twenty-five  species  of  cellulose-dissolving  bacteria  have  been 
grown  on  culture  media  containing  cellulose  prepared  from  alfalfa  flour. 
All  of  the  organisms  plated  to  this  medium  dissolved  the  cellulose  as 
readily  as  that  prepared  from  filter  paper. 

5.  All  of  the  cellulose-dissolving  organisms  studied  develop  most 
rapidly  in  the  presence  of  air,  although  more  or  less  growth  can  be  secured 
under  anaerobic  conditions. 

6.  Most  of  the  cellulose-destroying  bacteria  grow  well  upon  ordinary 
culture  media.  A  few  forms  do  not  grow  upon  ordinary  culture  media, 
but  only  upon  media  containing  cellulose. 

7.  The  cellulose-dissolving  bacteria  assimilate  nitrogen  from  organic 
as  well  as  inorganic  nitrogenous  compounds.  Many  forms  destroy  cellu- 
lose rapidly  when  the  culture  medium  contains  nitrogen  in  the  form  of 
peptone,  ammonium  sulphate,  potassium  nitrate  or  casein.  Peptone  ap- 
pears to  be  most  favorable  for  the  largest  number  of  species,  while  casein 
is  usually  least  favorable  of  the  nitrogen  compounds  tested. 

8.  The  quantity  of  acid  formed  in  carbohydrate  broths,  in  12  days  at 
30*^  C.  usually  amounts  to  from  1  to  2  per  cent  on  Fuller's  scale,  with 
dextrose,  lactose,  maltose,  saccharose,  and  starch.  The  per  cent  of  acid- 
ity in  mannite  and  glycerine  solutions  is  usually  less  than  1  per  cent  and  in 
many  instances  no  acid  is  formed  from  these  substances. 

9.  Many  species  of  cellulose-dissolving  bacteria  produce  a  small 
quantity  of  nitrite  in  Dunham's  solution.  The  nitrite  is  presumably 
formed  from  the  peptone.  A  starch  nitrate  broth  free  from  peptone  has 
therefore  been  used  instead  of  the  standard  nitrate  broth  for  determining 
the  nitrate  reducing  power  of  these  organisms. 

10.  Filamentous  fungi  play  a  much  more  important  role  in  the  de- 
struction of  cellulose  in  the  humid  soils  of  the  eastern  part  of  the  United 
States  than  in  the  semi-arid  soils  of  southern  California. 

11.  Species  of  cellulose-dissolving  Actinomyces  have  a  wide  distri- 
bution in  soils  and  are  unquestionably  a  factor  in  the  destruction  of 
cellulose  in  nature, 

12.  The  very  rapid  destruction  of  cellulose  which  occurs  in  many 
soils  of  southern  California  is  probably  due  to  favorable  climatic  and  cul- 
tural conditions  which  make  possible  the  rapid  development  of  the  cellu- 
lose-dissolving organisms  rather  than  to  the  unusually  active  nature  of 
the  cellulose-dissolving  soil  flora. 


THE  DECOMPOSITION  OF  CELLULOSE  IN  SOILS  481 

Acknowledgements 

The  studies  reported  in  tliis  paper  were  submitted  to  the  Faculty  of 
the  Graduate  School  of  the  University  of  CaHfornia  in  partial  fulfilment 
of  the  requirements  for  the  degree  of  doctor  of  philosophy,  March,  1916. 

The  writer  wishes  to  extend  his  thanks  to  Dr.  C.  B.  Lipman  and  Dr. 
J,  T.  Barrett  for  many  valuable  suggestions  offered  from  time  to  time, 
and  for  the  great  interest  shown. 

LITERATURE  CITED 

(1)  Appel,  Otto,  and  Schikorra,  G. 

1906.  Beitrage  zur  Kenntnis  der  Fusarien  und  der  von  ihnen  hervorgeru- 
fenen  Pflanzenkrankheiten.  In  Arb.  K.  Biol.  Anst.  Land-u. 
Forstw.,  Bd.  5,  No.  4,  p.  155-156. 

(2)  Arzberger,  E.  G. 

1909.  The   fungus  root-tubercles    of    Ceanothus    americanus,    Elaeagniis 

argentea,  and  Myrica  cerifera.    In  Mo.  Bot.  Gard.  21st  Ann.  Rpt., 
p.  60-102,  pi.  6-14.     Index  of  literature,  p.  97-100. 

(3)  Bary,  Anton  de 

1863.  Recherches  sur  le  developpement  de  quelques  champignons  para- 
sites.   In  Ann.  Sci.  Nat.  Bot.,  s.  4,  t.  20,  p.  1-148. 

(4)  Bary,  Anton  de 

1886.  Ueber  einige  Sclerotinien  und  Sclerotienkrankheiten.  In  Bot.  Ztg., 
Bd.  44,  No.  22,  p.  Z77-2>?>7,  illus. ;  No.  23,  p.  393-404 ;  No.  24,  p.  409- 
426 ;  No.  25,  p.  433-441 ;  No.  26,  p.  449-461 ;  No.  27,  p.  465-474. 

(5)  Behrens,  J. 

1898.  Beitrage  zur  Kenntnis  der  Obstfaulnis.  In  Centbl.  Bakt.  [etc.],  Abt. 
2,  Bd.  4,  No.  12,  p.  514-522;  No.  13,  p.  547-553;  No.  14,  p.  577-585; 
No.  15/16,  p.  635-644;  No.  17/18,  p.  700-706;  No.  19,  p.  739-746. 

(6)  Berthelot,  M.  p.  E. 

1889.  Observations  sur  la  communication  precedente.  In  Compt.  Rend. 
Acad.  Sci.  [Paris],  t.  109,  no.  23,  p.  841-842. 

(7)  Bertrand,  Gabriel,  and  Holderer,  M. 

1910.  Recherches   sur  la  cellase  nouvelle  diastase  dedoublant  le  cellose. 

In  Ann.  Inst.  Pasteur,  t.  24,  p.  180-188. 

(8)  BOURQUELOT,   EmILE. 

1893.  Les  ferments  solubles  de  1'  "Aspergillus  niger."  In  Bui.  Soc.  Mycol. 
France,  t.  9,  p.  230-238. 

(9)  Choukevitch,  Jean. 

1911.  Etude  de  la  flore  bacterienne  du  gros  intestin  du  cheval.     In  Ann. 

Inst.  Pasteur,  t.  25,  no.  3,  p.  247-276. 

(10)  Christensen,  H.  R. 

1910.  Ein  Verfahren  zur  Bestimmung  der  zellulosezersetzenden  Fahig- 
keit  des  Erdbodens.  In  Centbl.  Bakt.  [etc.],  Abt.  2,  Bd.  27,  No. 
17/21,  p.  449-451. 

(11)  Christensen,  H.  R. 

1913.  Untersuchungen  betreffs  der  Zellulose  zersetzenden  Fahigkeit.  In 
Centbl.  Bakt.  [etc.],  Abt.  2,  Bd.  37,  No.  14/16,  p.  423-425. 

(12)  Christensen,  H.  R. 

1915.  Untersuchungen  iiber  die  zellulosezersetzende  Fahigkeit  des  Bodens 
in  ihrem  Verhaltnis  zur  Bodenbeschaffenheit.  In  Centbl.  Bakt. 
[etc.],  Abt.  2,  Bd.  43,  No.  1/7,  p.  92-134. 


482  SOIL  SCIENCE 

(13)  Deherain,  p.  p. 

1884.     Recherches   sur  les   fermentations   du    fumier   de   fei-me.     In   Ann. 
Agron.,  t.  10,  p.  385-409. 

(14)  DisTASo,  A. 

1911.  Sur  un  microbe  qui  desagrege  la  cellulose  (Bacillus  cellulosae  desa- 

gregans,  n.  sp.,).  In   Compt.    Rend.   Soc.  Biol.    [Paris],  t.  70,  no. 
22,  p.  995-996. 

(15)  Gayon,  Ulysse. 

1884.     Recherches  sur  la  fermentation  du  fumier.    In  Compt.  Rend.  Acad. 
Sci.  [Paris],  t.  98,  no.  8,  p.  528-531. 

(16)  Gayon,  Ulysse. 

1884.  (Studies  of  methane   fermentation.)     In  Mem.    Soc.   Sci.  Phys.   et 

Nat.  Bordeaux,  s.  3,  t.  1,  p.  51-52. 

(17)  Hartig,  Robert. 

1878.     Die  Zersetzungserscheinungen  des  Holzes  der  Nadelholzbaume  und 
der  Eiche.  151  p.,  21  pi.  Berlin. 

(18)  Haubner,  Karl. 

1854.     (Experiments  on  the  digestibility  of  cellulose  by  ruminants. )i     In 
Amts-  und  Anzbl.  Landw.  Ver.  Konigr.  Sachsen. 

(19)  Haubner,  Karl  and  Sussdorf. 

1859.     Fiitterungsversuche  iiber  die   Verdaulichkeit  der   Pflanzenfaser  bei 
Schafen.    In  Ber.  Verterinarw.  Konigr.  Sachsen,  1860,  p.  104-107. 

(20)  Herbert,  A. 

1892.     Etudes   sur  la  preparation   du    fumier.     In  Ann.   Agron.,   t.    18,  p. 
536-550. 

(21)  Henneberg,  J.  W.  J.,  and  Stohmann,  Friedrich. 

1860-1864.     Beitrage  zur  Begriindung  einer  rationellen  Fiitterung  der  Wie- 
derkauer.  2  pts.  Braunschweig. 

(22)  Henneberg,  J.  W.  J.,  and  Stohmann,  Friedrich. 

1885.  Ueber  die  Bedeutung  der  Cellulose-Garung  fiir  die  Ernahrung  der 

Thiere.    In  Ztschr.  Biol,  Bd.  21  (n.  R.  Bd.  3),  p.  613-624. 

(23)  Hofmeister,  Victor. 

1881.     Ueber  Celluloseverdauung.     In   Arch.   Wiss.   u.   Prakt.    Thierheilk., 
Bd.  7,  No.  3,  p.  169-197. 

(24)  Hofmeister,  Victor. 

1885.  Ueber  Celluloseverdauung  beim  Pferde.     In  Arch.  Wiss.  u.  Prakt. 

Thierheilk.,  Bd.  11,  No.  1/2,  p.  46-60. 

(25)  Hoppe-Seyler,  Felix. 

1883.     Ueber  Garung  der  Cellulose.     In  Ber.  Deut.  Chem.  Gesell.,  Bd.  16, 
p.  122-123. 

(26)  Hoppe-Seyler,  Felix. 

1886.  Ueber  Garung  der  Cellulose  mit  Bildung  von  Methan  Und  Kohlen- 

siiure.     In  Ztschr.  Phys.  Chem.   (Hoppe-Seyler),  Bd.  10,  No.  3,  p. 
201-217;  No.  5,  p.  401-440. 

(27)  Iterson,  Gerrit  Van,  Jr. 

1904.     Die  Zersetzung  von  Cellulose  durch  Aerobe  Mikroorganismen.     In 
Centbl.  Bakt.  [etc.],  Abt.  2,  Bd.  11,  No.  23,  p.  689-698. 

(28)  Kellerman,  K.  F. 

1912.  Formation  of  cytase  by  Penicillium  Pinophiliim.     In   U.    S.   Dept. 

Agr.  Bur.  Plant  Indus.  Circ.  113,  p.  29-31. 

^  Original  article  not  obtainable. 


THE  DECOMPOSITION  OF  CELLULOSE  LV  SOILS  483 

(29)  Kellerman,  K.  F.,  and  ^.IcBeth,  I.  G. 

1912.  The  fermentation  of  cellulose.     In  Centbl.  Bakt.   [etc.],  Abt.  2,  Bd. 

34,  No.  18/22,  p.  485-494. 

(30)  Kellerm.\n,  K.  R,  McBeth,  I.  G.,  Sc.\les,  F.  M.  and  Smith,  N.  R. 

1913.  Identification   and   Classification   of   Cellulose — Dissolving  Bacteria. 

In  Centbl.  Bakt.  [etc.],  Abt.  2,  Bd.  39,  No.  20/22.  p.  502-522,  2  pi. 

(31)  KiSSLING,  E. 

1889.  Zur  Biologie  der  Botrytis  cinerea.  Inauguraldissertation,  32  p. 
Dresden. 

(32)  Knieriem,  Waldemar  Von. 

1885.  Ueber  die  Verwerthung  der  Cellulose  im  thierschen  Organismus.  In 
Ztschr.  Biol.,  Bd.  21,  (n.  R.  Bd.  3),  p.  67-139. 

(33)  Koch,  Alfred. 

1910.  Stickstoflfgewinn  und  Stickstoffverlust  im  Ackerboden.  In  Mitt. 
Deut.  Landw.  Gesell.,  No.  12,  p.  173-175. 

(34)  Koch,  Alfred. 

1910.  Uber  Luftstickstoffindung  im  Boden  mit  Hilfe  von  Zellulose  als 
Energiematerial.  In  Centbl.  Bakt.  [etc.],  Abt.  2,  Bd.  27,  No.  1/3, 
p.  1-7. 

(35)  Krainsky,  a. 

1913.  Zur    Frage    der    Zellulosezersetzung    durch    Mikroorganismen.      In 

Zhur.  Opuitn.  Agron.   (Russ.  Jour.  Expt.  Landw.),  Bd.  14,  No.  4, 
255-261. 

(36)  Krainsky,  a. 

1914.  Die  Aktinomyceten   imd  ihre  Bedeutung  in  der  Natur.     In  Centbl. 

Bakt.  [etc.],  Abt.  2,  Bd.  41.  No.  24/25,  p.  649-688,  2  pi. 

(37)  Kroulik,  Alois. 

1912.  Uber  thermophilc  Zellulosevergarer.     In  Centbl.  Bakt.  [etc.],  Abt.  2, 

Bd.  36,  No.  6/14,  p.  339-346. 

(38)  KuHN,  J.  G. 

1859.  Die  Krankheiten  der  Kulturgevviichse,  ihre  Ursachen  und  ihre  Ver- 
hiitung.  2nd  ed.,  312  p.,  7  pi.  Berlin. 

(39)  Lehmann,  Franz,  and  Vogel,  J.  H. 

1889.     Versuche  ul)er  die  Bedeutung  der  Cellulose  als  Nahrstoff.     In  Jour. 
Landw..  Bd.  37,  p.  251-326. 
(39a)  Lipman,  C.  B.  and  Waynick,  D.  D. 

1916.  A  Detailed  Study  of  Effects  of  Climate  on  Important  properties  of 
Soils.    In  Soil  Sci.  v.  1,  no.  1,  p.  5-48,  5  pi. 

(40)  Lohnis,  p.,  and  Lochhead,  Grant. 

1913.  Uber  Zellulose-zersetsung.     In  Centbl.  Bakt.    [etc.],  Abt.  2,  Bd.  37, 

No.  17/21,  p.  490-492. 

(41)  Macf.wden,  Allan,  and  Blaxall,  F.  R. 

1899.  Thermophilic  bacteria.  In  Trans.  Jenner  Inst.  Prev.  Med.,  ser.  2, 
p.  162-187,  3  pi.     References,  p.  186-187. 

(42)  McBeth,  I.  G. 

1913.  Cellulose  as  a  source  of  energy  for  nitrogen  fixation.  In  U.  S. 
Dept.  Agr.  Bur.  Plant  Indus.  Circ.  131,  p.  25-34. 

(43)  McBeth,  I.  G.,  and  Scales,  F.  M. 

1913.  The  destruction  of  cellulose  by  bacteria  and  filamentous  fungi.  U. 
S.  Dept.  Agr.  Bur.  Plant  Indus.  Bui.  266. 


484  SOIL  SCIENCE 

(44)  McBeth,  I  .G.,  Scales,  F.  M.,  and  Smith,  N.  R. 

1913.  Characteristics  of  cellulose-destroying  bacteria.  In  Science,  n.  s.  v. 
38,  no.  977,  p.  415. 

(45)  Merker,  Emil. 

1912.  Parasitische  Bakterien  auf  Blattern  von  Elodea.     In  Centbl.  Bakt. 

[etc.],  Abt.  2,  Bd.  31,  No.  23/25,  p.  578-590. 

(46)  MiTSCHERLICH. 

1850.  Zusammensetzung  der  Wand  der  Pflanzenzelle.  Bericht  iiber  die  zur 
Bekanntmachung  geeigneten  Verhandlungen  der  Koniglichen 
Preussischen  Akademie  der  Wissenschaften  zu  Berlin,  p.  102-110. 

(47)  MiYOSHi,  Manabu. 

1894.  Ueber  Chemotropismus  der  Pilze.    In  Bot,  Ztg.,  Bd.  52,  p.  1-28,  pi.  1 

(48)  MUTTERLEIN,   C. 

1913.  Studien  iiber  die  Zersetzung  der  Zellulose  im  Diinger  und  Boden. 

Inauguraldissertation,  Leipsic.  Abs.     In  Centbl.  Bakt.   [etc.],  Abt. 
2,  Bd.  39,  No.  4/7,  p.  167-169. 

(49)  Nylander,  William. 

1865.     Sur  les  amylobacter.    In  Bui.  Soc.  Bot.  France,  t.  12,  p.  395-396. 

(50)  Omelianski,  W. 

1895.  Sur  la  fermentation  de  la  cellulose.     In  Compt.  Rend.  Acad.   Sci. 

[Paris],  t.  121,  no.  19,  p.  653-655. 

(51)  Omelianski,  W. 

1897.  Sur  la  fermentation  cellulosique.  Compt.  Rend.  Acad.  Sci.  [Paris],  t. 
125,  no.  25,  p.  1131-1133. 

(52)  Omelianski,  W. 

1897.  Sur  un  ferment  de  la  cellulose.  Compt.  Rend.  Acad.  Sci.  [Paris], 
t.  125,  no.  23,  p.  970-973. 

(53)  Omelianski,  W. 

1899.  Sur  la  fermentation  de  la  cellulose.  Arch.  Sci.  Biol.  [St.  Petersb], 
t.  7,  p.  411-434,  pi.  7. 

(54)  Omelianski,  W. 

1902.  Ueber  die  Garung  der  Cellulose.  In  Centbl.  Bakt.  [etc.],  Abt.  2,  Bd. 
8,  No.  7,  p.  193-201 ;  No.  8,  p.  225-231 ;  No.  9,  p.  257-263 ;  No.  10, 
p.  289-294;  No.  11,  p.  321-326;  No.  12,  p.  353-361;  No.  13,  p.  385- 
391,  1  fig.,  1  pi. 

(55)  Omelianski,  W. 

1904.  Die  Histologischen  und  Chemischen  Veranderungen  der  Leinsten- 
gel  unter  Einwirkung  der  Mikroben  der  Pektin — und  Cellulose- 
garung.  In  Centbl.  Bakt.  [etc.],  Abt.  2,  Bd.  12,  No.  1/3,  p.  33-43, 
Ipl. 

(56)  Omelianski,  W. 

1904.  Ueber    die    Trennung    der    Wasserstoff — und    Methangarung     der 

Cellulose.     In  Centbl.  Bakt.   [etc.],  Abt.  2,  Bd.  11,  No.  12/13,  p. 
369-377. 

(57)  Omelianski,  W. 

1905.  Die   Cellulosegarung.     In  Lafar,   Franz,  Handb.   Tech.  Mykol.  2d., 

ed.,  Bd.  3,  Heft.  6,  p.  245-268,  fig.  37-39,  pi.  7. 

(58)  Omelianski^  W. 

1906.  Ueber  Methanbildung  in  der  Natur  bei  biologischen  Prozessen.    In 

Centbl.  Bakt.  [etc.],  Abt.  2,  Bd.  15,  No.  22/23,  p.  673-687. 

(59)  Omelianski,  W. 

1913.  Zur  Frage  der  Zellulosegarung.  In  Centbl.  Bakt.  [etc.],  Abt  2, 
Bd.  36,  No.  19/25,  p.  472,  473. 


THE  DECOMPOSITION  OF  CELLULOSE  IN  SOILS  485 

(60)  Pasteur,  Louis. 

1857.  Memoire  sur  la  fermentation  appelee  lactique.  Compt.  Rend.  Acad. 
Sci.  [Paris],  t.  45,  no.  22,  p.  913-916. 

(61)  PoPOFF,  Leo. 

1875.  Ueber  die  Sumpfgasgahrung.  Arch.  Gesam.  Physiol.  (Pfliiger),  Bd. 
10,  p.  113-146. 

(62)  Prazmowski,  Adam. 

1880.  Untersucliiingen  uber  die  Entwickelungsgeschichte  und  Fermenwir- 
kung  einiger  Bacterien-Arten,  p.  58,  2  pi.  Leipzig. 

(63)  Pringsheim,  Hans. 

1909.  Ueber  die  Verwendung  von  Cellulose  als  Energiequelle  zur  Assimi- 

lation des  Luftstickstoffs.     In  Centbl.  Bakt.  [etc.],  Abt.  2,  Bd.  23, 
No.  10/13,  p.  300-304. 

(64)  Pringsheim,  Hans. 

1910.  Weiteres  uber  die  Verwendung  von  Cellulose  als  Energiequelle  zur 

Assimilation  des  LuftstickstoflFs.     In  Centbl.  Bakt.   [etc.],  Abt.  2, 
Bd.  26,  No.  6/7,  p.  222-227. 

(65)  Pringsheim,  Hans. 

1912.  Uber  den   fermentativen   abbau  der  Zellulose.     In  Ztschr.   Physiol. 

Chem.  (Hoppe-Seyler),  Bd.  78,  p.  266. 

(66)  Pringsheim,  Hans. 

1913.  Uber  die  Vergiirung  der  Zellulose  durch  thermophile  Bakterien.    In 

Centbl.  Bakt.  [etc.],  Abt.  2,  Bd.  38,  No.  21/25,  p.  513-516,  fig.  1. 

(67)  Pringsheim,  Hans. 

1913.  Die  Beziehungen  der  Zellulosezersetzung  sum  stickstoffhaushalt  in 
der  Natur.  In  Mitt.  Deut.  Landw.  Gesell.,  Bd.  28,  No.  2,  p.  26-29; 
No.  3,  p.  43-45 ;  No.  20,  p.  295-296. 

(68)  Rahn,  Otto. 

1913.  Die  Baketerientatigkeit  im  Boden  als  Funktion  der  Nahrungsko- 
zentration  und  der  unloslichen  organischen  Substanz.  In  Centbl. 
Bakt.   [etc.],  Abt.  2,  Bd.  38,  No.  19/20,  p.  484-494. 

(69)  Reinke,  Johannes,  and  Berthold,  G.  D.  VV. 

1879.  Die  Zersetsung  der  Kartoffel  durch  Pilze.  p.  100,  9  pi.  Berlin.  Un- 
tersuchungen  aus  dem  Botanischen  Laboratorium  der  Universitat 
Gottingen,  No.  1. 

(70)  Reiset,  Jules. 

1856.  Experiences  sur  la  putrefaction  et  sur  la  formation  des  fumiers.  In 
Compt.  Rend.  Acad.  Sci.    [Paris],  t.  42,  no.  2,  p.  53-59. 

(71)  Scales,  Freeman  M. 

1915.  Some  Filamentous  fungi  tested  for  cellulose  destroying  power.  In 
Bot.  Gaz.  V.  60,  no.  2,  p.  149-153. 

(72)  Scales,  Freeman  M. 

1915.  A  new  method  of  precipitating  cellulose  for  cellulose  agar.  In 
Centbl.  Bakt.  [etc.],  Abt.  2,  Bd.  44,  No.  17/23,  p.  661-663. 

(73)  Schellenberg,  H.  C. 

1908.  Untersuchungen  iiber  das  Verhalten  einiger  Pilze  gegen  Hemizel- 
lulosen.    In  Flora,  Bd.  98,  No.  3,  p.  257-308. 

(74)  Schloesing,  Theophile,  pcre 

1889.  Sur  la  fermentation  formenique  du  fumier.  In  Compt.  Rend.  Acad. 
Sci.  [Paris],  t.  109,  n.  23,  p.  835-840. 

(34) 


486  SOIL  SCIENCE 

(75)  ScHLOESiNG,  Theophile,  fils,  and  Schloesing,  Theophile,  pere. 

1892.  Contribution  a  1'  etude  des  fermentations  du  fumier.  In  Ann. 
Agron.,  t.  18,  p.  5-18. 

(76)  Senus,  a.  H.  C.  Van. 

1890.  Bijdrage  tot  de  Kennis  der  Cellulosegisting.i  p.  188,  2  pi.  Proef- 
schrift.  Leyden,  Abs.  In  Jahresber.  Fortschr.  Lehr.  Gahrungs- 
Organismen  (Koch),  Bd.  1,  p.  136-139. 

(77)  Smith,  E.  F. 

1902.     Destruction  of  cell  walls  by  bacteria.    In  Science,  n.  s.  v.  15,  p.  405. 

(78)  Tappeiner,  Hermann. 

1881.  Die  Darmgase  der  Pflanzenfresser.   In  Ber.  Deut.  Chem.  Gesell.,  Bd. 

14,  Oct.,  p.  2375-2381. 

(79)  Tappeiner,  Hermann. 

1882.  Ueber   Celluloseverdauung.     In   Ber.   Deut.    Chem.   Gesell.,   Bd.    15, 

Apr.,  p.  999-1002. 

(80)  Tappeiner,  Hermann. 

1883.  Die  Gase  des  Verdauungsschlauches  der  Pflanzenfresser.    In  Ztchr. 

Biol,  Bd.  19,   (n.  R.  Bd.  1),  p.  228-279. 

(81)  Tappeiner,  Hermann. 

1884.  Untersuchungen  iiber   die  Garung  der   Cellulose  insbesondere  iiber 

deren  Losung  im  Darmkanale.    In  Ztschr.  Biol.,  Bd.  20,  (n.  R.  Bd. 
2),  p.  52-134. 

(82)  Tappeiner,  Hermann. 

1888.  Nachtrage  zu  den  Untersuchungen  iiber  die  Garung  der  Cellulose. 
In  Ztschr.  Biol.,  Bd.  24,  (n.  R.  Bd.  6),  p.  105-119. 

(83)  Trecul,  a. 

1865.  Matiere  amylacee  et  cryptogames  amyliferes  dans  les  vaisseaux  du 
latex  de  plusieurs  Apocynees.  In  Compt  Rend.  Acad.  Sci.  [Paris], 
t.  61,  no.  4,  p.  156-160. 

(84)  Trecul,  a. 

1865.  Production  de  plantules  amyliferes  dans  les  cellules  vegetales  pen- 
dant la  putrefaction.  Chlorophylle  cristallisee.  In  Compt.  Rend. 
Acad.  Sci.  [Paris],  t.  61,  no.  11,  p.  432-436. 

(85)  Trecul,  A. 

1867.  Reponse  a  trois  notes  de  M.  Nylander  concernant  la  nature  des  amy- 
lobacter.  In  Compt.  Rend.  Acad.  Sci.  [Paris],  t.  65,  no.  13,  p. 
513-521. 

(86)  Tulasne,  L.-R. 

1854.  Second  memoire  sur  les  uredinees  et  les  ustilaginees.  In  Ann.  Sci. 
Nat.  Bot.,  s.  4,  t.  2,  p.  77-196,  pi.  7-12. 

(87)  Van  Tieghem,  P.  E.  L. 

1877.  Sur  le  Bacillus  amylobacter  et  son  role  dans  la  putrefaction  des  tis- 
sus  vegetaux.    In  Bui.  Soc.  Bot.  France,  t.  24,  p.  128-135. 

(88)  Van  Tieghem,  P.  E.  L. 

1879.  Identite  du  Bacillus  amylobacter  et  du  virbrion  butyrique  de  M. 
Pasteur.    In  Compt.  Rend.  Acad.  Sci.  [Paris],  t.  89,  no.  1,  p.  5-8. 

(89)  Van  Tieghem,  P.  E.  L. 

1879.  Sur  le  ferment  butyrique  (Bacillus  amylobacter)  a  1'  epoque  de  la 
houille.  In  Compt.  Rend.  Acad.  Sci.  [Paris],  t.  89,  no.  26,  p.  1102- 
1104. 

*  Original  article  not  obtainable. 


THE  DECOMPOSITION  OF  CELLULOSE  IN  SOILS  487 

(90)  Van  Tieghem,  P.  E.  L. 

1879.  Sur  la  fermentation  de  la  cellulose.  In  Compt.  Rend.  Acad.  Sci. 
IParisJ,  t.  88,  no.  5,  p.  205-210. 

(91)  Van  Tieguem,  P.  E.  L. 

1881.  Remarques  sur  1'  etat  o'u  se  trouvent  les  graines  silicifiees  dans  le 
terrain  houiller  de  Saint-Etienne.  In  Bui.  Soc.  Bot.  France,  t.  28, 
(s.  2,  t.  3),  p.  243-245. 

(92)  Ward,  H.  M. 

1888.     A  lily-disease.    In  Ann.  Bot.  v.  2,  no.  7,  p.  319-382,  pi.  20-24. 

(93)  Ward,  H.  M. 

1898.  Penicillium  as  a  wood-destroying  fungus.  In  Ann.  Bot.  v.  12,  no.  48, 
p.  565-566. 

(94)  Weiske,  Hugo. 

1870.     Untersuchungen  iiber  die  Verdaulichkeit  der  Cellulose  beim  Men- 

schen.     In  Ztschr.  Biol.,  Bd.  6,  p.  456-466. 
(95)' Weiske,  Hugo. 

1884.     1st  die  Cellulose  ein  Nahrungstoff  ?    In  Chem.  Centbl.,  s.  3,  Bd.  15, 

No.  21,  p.  385-386. 

(96)  Weiske,  Hugo. 

1888.  Kommt  der  Cellulose  eiweissersparende  Wirkung  bei  der  Ernjih- 
rung  der  Herbivoren  zu?  In  Ztschr.  Biol.,  Bd.  24,  (n.  R.  Bd.  6), 
p.  553-561. 

(97)  Weiske,  Hugo.,  Schulze,  B.,  and  Flechsig. 

1886.  Kommt  der  Cellulose  eiweissparende  Wirkung  bei  der  Ernahrung 
der  Herbivoren  zu?  In  Ztschr.  Biol,  Bd.  22  (n.  R.  Bd.  4),  p. 
373-403. 

(98)  ZuNTz,  Nathan. 

1879.  Gesichtspunkte  zum  kritischen  studium  der  neueren  Arbeiten  auf 
dem  Gebiete  der  Ernahrung.  In  Landw.  Jahrb.,  Bd.  8,  No.  1,  p. 
65-117. 

(99)  ZuNTZ,  Nathan. 

1891.  Bemerkungen  iiber  die  Verdauung  und  den  Nahrwerth  der  Cellulose. 
In  Arch.  Physiol.  [Pfliiger],  Bd.  49,  p.  477-483. 


LD  21-95jn.7,>37 


YD   16392 


UNIVERSITY  OF  CALIFORNIA  LIBRARY  ^| 

i 


i^u^niui 


(  f':-.>:'^*'l;('Mf^ 


^y'^'::H' 


•  '\.'Uli 


in:\\im'ii 


'\-:'-M- 


i'V    i' 


'■?; 


